Periods, irregular 


Menstrual cycle: animation

This animation explains in detail how the menstrual cycle works.

Media last reviewed: 21/02/2013

Next review due: 21/02/2015

When should I see my GP?

Talk to your GP if you have any of the following changes in your periods:

  • you have very heavy periods, where you need to change your tampon or pad every hour or two, or you have to wear both a pad and a tampon
  • your periods last longer than seven days
  • there are fewer than three weeks between the start of one period and the next
  • you have bleeding or spotting between periods
  • you are bleeding after sex

Some women find their menstrual cycle isn't always regular. Their periods may be early or late, and may vary in how long they last or how heavy they are each time.

Your normal menstrual cycle can be disturbed if you change your method of contraception or if you have an imbalance of the reproductive hormones oestrogen and progesterone.

Many factors can cause a hormone imbalance, from polycystic ovary syndrome to extreme weight loss and excessive exercise.

Read more information about the causes of irregular periods.

Treating irregular periods

Irregular periods are common during puberty or just before the menopause. Treatment during these times is not usually necessary.

But if you're worried because your periods are particularly heavy, last a long time or are more frequent than monthly, or if you get bleeding or spotting between periods or after sex, see your GP.

You may need a different contraceptive or be investigated for an underlying health condition.

Read more information about treating irregular periods.

The average menstrual cycle

The average menstrual cycle lasts 28 days, but can vary between 24 and 35 days.

After puberty, most women develop a regular menstrual cycle, with around the same length of time between periods.

Menstrual bleeding normally lasts between two and seven days, with the average being five days. 

More information on periods and period problems

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Page last reviewed: 04/04/2013

Next review due: 04/04/2015


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The 47 comments posted are personal views. Any information they give has not been checked and may not be accurate.

skyscraper822 said on 14 October 2014

Hi everyone, I'm 14 and have been experiencing irregular periods about after 2 months having them (i started in May 2013) and then suddenly they stopped, I went on holiday and didn't experience one single period! I ad irregular spotting near my birthday but it was only pink water, they came back in January 2014 but it was only light brown discharge they came back properly in February since then I have been missing every other month and they only come for 3-5 days, my GP said maybe because my weight dropped dramatically and I had become underweight maybe because of that but it's been somewhat a year now so I don't know what's happening, I'm not really stressed but I don't know if this is going to affect my future, I don't really care if my periods come or not but I have a feeling that this is somehow going affect me greatly.
I've been reading everyone's personal stories and I really get motivated this is a great site and good luck to all you going through this!

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workygirl said on 10 July 2014

I am 44 and the older I'm getting the closer together and heavier my periods are getting. They have gone from 28-30 days lasting around 3-5 days. over the last 2 years they have become closer, every 21-24 days (ugh!) and last from 5-7 days although these are pretty regular, but so painful.

However, this month I started my cycle last Thursday and it has lasted 6 days, it was a particularly heavy period for at least 3 days of the 6, with terrible pains for 3 days.

It now seems, that nearly 2 days later, it has started again, with period pains. I've never had this before.

I'm not pregnant, or taking any kind of medication, my life is pretty normal and boring!

any idea why this may be happening.

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Sally2468 said on 17 June 2014

I am 42 this month and I have had irregular periods since I was ten yrs old. Some have been heavy and prolonged and some not. 13 yrs ago I had an eptopic where my baby died in the tube. Since then I was told that I would probably not be able to get pregnant, they never told me never but they said that it would be difficult due to scaring from numerous bowel surgerys back in 2005. I last had a period on the 3rd May then I haa show on the 31st May, usually I get upset tummy 7 days before, all I had was pinkish water, nothing on my pad but only if I pressed some tissue up underneath which was alittle red, on and off for 3-4 days just every now and then I would pass pink water.
I have been extremly tierd, alittle cramping but nothing to worry about, can this happen if your pregnant, I hope so as its my last hope!

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Girl1223 said on 15 April 2014

I am 17 and last year, because a mixture of the stress of my exams and losing about a stone in weight, I lost my period. It was gone for about 11 months and has just come back. I have had 3 cycles now since losing it a year ago, and they have come less than 3 weeks apart each time - and I think I might my 4th period tomorrow which would be about two weeks since my last. I started my period when I was 13 and it was never regular (coming about every 5- 8 weeks or so). I was considered underweight when I lost my period (according to BMI although I wasn't obviously underweight) and now that I have it back, even though I don't eat any more, I have put on around 5 pounds and it is coming every 2 - 3 weeks. Is this normal, is it my period trying to 'catch up' (I know that sounds stupid but i am not sure why it is so regular!)?

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Savgirl said on 15 April 2014

I'm 16 and basically in January I had stop taking the pill so I could have my monthly cycle. However it didn't come, and it didn't come for a month however I got told I was pregnant by a nhs doctor, and it turned out I weren't even pregnant. The past 3months of my period were normal, however I've been on my period for a month now and no clue what to do, I'm currently on the pill but it's very worrying as my period just won't stop

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Miss007 said on 23 March 2014

Allyyyy009. This happened to me as well. About 5 years ago. I was on the depo contraceptive as well and decided to come of it. My periods became very irregular and the doc put me on the pill to try to kick start them into a regular pattern again. It didn't work. Don't want to scare you but my period lasted 6 months non stop (very annoying and inconvenient) with maybe a couple of small beaks inbetween (around 3-4 days) It did eventually stop though and I eventually got back to a regular routine around 3 months later. Sounds as though you have a good doc tho. Mine didn't do any tests and just shrugged his shoulders and said it would eventually return to normal. I hope you have more luck than I did and yours returns to normal sooner than that though.

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Shannon95x said on 15 March 2014

Hi, I'm years old and suffer really badly from painful and irregular periods. My periods fluctuate each month ranging from 44 days down to 32 and sometimes even longer. Lately they've been extremely painful and I am clotting quite a lot. Is this something I should speak to my doctor about?

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Elchy1 said on 04 March 2014

Nuttymeg hi, I'm 36 & having similar symptoms had nightsweats for about 3yrs now. 1st hormone test showed I was premenopausal, apparently that's common in the very early stages, periods are now shorter 21 day cycle last about 3 days until this month started on day 18 lasted 5 days , I get hot flushes during the day now too & brain fog oh memory loss as well. Dr has done another full blood test, hormones, thyroid, iron just waiting for results & a scan to rule out endo or fibroids again awaiting appointment. U said ur test said u are menopausal & asked if u r in perimenopause ? I'm sure if u are perimenopausal that means u can still get pregnant if u r ovulating the Drs should have been more clear as to which stage of menopause ur in. I wish u luck

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Allyyyy009 said on 21 February 2014

Hi I am 20 years old and I was wondering if anyone had the same problem as me? I used to be on depo provera but stopped that sept 2013 I was on the injection for 9 months when I decided to transfer onto the pill. I was on the pill beginning of sept 2013 - beginning of nov 2013 I came off the pill as me and my fiancé want to start a family.. I had my withdrawal bleed after coming off the pill that was normal then I didn't have any bleeding at all until the middle of December 2013! When I did start bleeding it has been non-stop and it's now the end of February! I had a proper period 2 weeks ago as it was much heavier and more like a period compared to the other bleeding I was experiencing that lasted 11 days then I had 5 days of bleeding free! I Thought everything was back to normal again until today I've come on my period again! I've been to the docs and I've had ultrasounds, blood tests, internal examinations and everything is normal! Also been put on tranexamic acid by they don't work! Now the docs are saying there's nothing else they can do for me! Has anyone got any advice? Or the same problem as me?

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Nuttymeg said on 28 January 2014

I'm 38 and for the past 2 years have been having irregular periods. They range from anywhere between 25 and 42 days. Also they are shorter and lighter than they used to be. I have 4 children whom i conceived very easily, yet i have been trying for a baby for 19 months now with my new husband, with no success. Iv'e had hormone blood tests recently the results have come back as menopausal. But i'm only 38! Have vaginal dryness some days, and night sweats, panic attacks and palpitations. Also i always feel tired and moody. Also, my hair is drier and falls out a lot. Could this really be perimenopause ? Really don't want it to be as i desperately want another child for my husband who has no children.

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kelly333 said on 12 January 2014

Hi im 25 and im having trouble with my periods and that whole area in general, I was quiet regular for about 4 months every month I knew when I was due but for the past 6 months I have been 2 days early each time, but the time before last I was late by a week and the pain was nothing like I had experienced before shooting all down my left leg ( that morning my left side of my abdomin was swallon) then I was on but it was blood, blood for the first 12 hours or so. My last time I was on I was a day late and only lasted 4 days which finished 7 days ago and now iam on again but its the smallest amount ever. The time before last I went to the doctors and he said I have pulled a groin muscle put because I refused to believe it he sent me for a scan which shows I have a cyst in my right overy, so then he says that he could keep and eye on it but will probably pass by its self. I have been in consent pain, like a cramping which happens about 3 out of 4 weeks and the pain at the top of my left leg/groin area nearly every day. Every doctor iv been to passes it off as ibs, o and I must mention I had treatment for CIN3 back in sept. Me and my partner are trying for a baby and have been since august are all these problems im having causing me not to conceive, I dont understand what is wrong but I know something is definitely wrong!

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charlottie44 said on 03 January 2014

Hi im 20 years old andI have been taking the pill for about 6 years up until about 3 months ago where I stopped for a while once I stopped I had a normal period then I started taking the pill again about 3 weeks ago then stopped on my break and came on my period as usual but haven't stopped bleeding now for about 2 weeks its been heavy and painful should i see a doctor or is this normal

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Danniee said on 29 December 2013

Im 20 and have been on the pill for 5 years.. Ive havent taken it for the last 7 months and my periods are really irregular my gap between eachone can be up to 50 days sometimes its driving me mad anyone no how long it takes before your bodies back to normal?

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sarewilson17 said on 27 December 2013

Hiya, I'm 17 and recently change my pill and have been having strange periods, the first period I had was two weeks into starting the pill and then two weeks later my next period came, it has been 5 days since then and I am now back on my pediod? I've been using the pill since the very early stages of my periods when I was 12/13. Not really sure what to do, just leave it or go to see the doctor, I am sexually active with my boyfriend of 3years, was cheecked for sti's on my last visit to the gun clinic, all results were negative? All help wanted! Thank you

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Dani x said on 28 October 2013

Hi there can anyone help I last had un protected sex on 28/07/2013 duuring overlation then in aug had 3 day bleed then sept had 3 day bleed now ots oct and im 7 days late last month had a faint second line on test then did anothet and negative plz help xx

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Jcostigan said on 08 October 2013

I have had irregular periods since I can remember, my periods lasts for months on end. I have been on my period now for 6 months, the pain is unbearable sometimes and i am extremely heavy, I have to were both tampons and 2-3 towels at a time and still come through with in 1-2 hours. I have been the doctors for the past two years and still don't seem to be getting anywhere. it is effecting my sex life, work, I don't even like going out because i know what will happen. Me and my partner have been also trying for a baby for a while, but obviously it interferes with are sex life, am worried I wont be able to have children, I constantly feel drained, I would love if anyone could offer me some advise or experience xx

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maxiej said on 03 September 2013

I'm 17, i was on the pill for 2 years but i came off it this January because i kept forgetting to take it. Since then my periods have been off, not coming on time. i didnt have one for 3 months at one point but then it came quite quickly after that. But since June my periods have been okay but i've missed one in august, im not sexually active so im not pregnant. I would just like to know if what im experiencing is normal? or shall i see my doctor about this?

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Samangie said on 11 August 2012

Hi I'm 24 years old, been off the pill 18 months. My periods are never regular. I can go 2 months without a period. I'm also trying for a baby is their anything I can do to help the situation as it's getting depressing never know when I'm coming on.

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tasha1993 said on 12 June 2012

Can someone help I'm 18 I fell pregnant at 16 and everything went according to plan I bled for 3 months afterwards and had 2 very irregular periods after that nnow 2 years on I haven't had a period atal I have certain symptoms like dizzyness tiredness weakness and palpitations please help x

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brentswifeyy said on 20 May 2012

I am a 24 year old... as of last year i have been haveing my period every two weeks. but for the past couple months they have been extremely heavy and stop about day 3 or 4. but come back later the same day or the next morning. i have pains in my lower left abdomen it feels nothing like cramps. but when my period starts back up its light than turns to brown within a matter of a couple hours, does anyone know what could be going on? i have not had my period the last month and a half almost than after i had sex with my fiancee all of a sudden it came full force like never before.. Please help if you can.....

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michelle379 said on 12 April 2012

I'm 36 and for as long as I can remember, my periods were irregular and heavy. Now they are constant. On average, I have a period approx every 2 weeks and they last up to 10 days. A majority of the time they are heavy. In my 20's I was on the pill and used to take them 'back to back' so I didn't have a period so often, but I have now found in my 30's that my body will just have a period, regardless of whether i'm still taking the pill or not. I was also given Depo injections but I had a constant period for 9 months (which was a very good contraceptive) so I was taken off it. I am constantly tired and just want to periods to stop all together and am considering having a hysterectomy to put my out of my misery...

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noreen46 said on 09 April 2012

since last i turned 45 last august i have had irregular periods. since then i have had none for a 2 months then one for 14 days. then since jan - mar 2012 no periods, but having a slow period since the 6/04/12 up to now having spot bleeding and slight heavy. really hot and bad headaches, nearly passed out when i went shopping. already suffer from migraines and panic attacks. sometimes argue with hubby, but he`s understanding and makes me laugh. will not go to chemist, as he say`s thats a womanly thing. found a white spot on my virginal lip yesterday, what can this be? i`m i going through the pre-menopause? as my mother when she was alive a few year back had the menopause at age of 52. trying to go to see female GP, but keep putting it off, help! have mood swings, not hungry, always drinking and pee-ing, feeling hot, dizziness, bad headaches,all alone and no family, hubby saying oh no women`s problems form age of 45 to 52, says women are sulky moody and moaners,. he also says women are witches, so i call him a baby when he`s bad and always sticks up for his mammy, all men are mamies boys ha-ha. also he suffers from headaches and i say your a big baby ha-ha

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Froufrou said on 03 April 2012

Hi im 25, Always had normal periods lasting 5 days once a month.
This month I have had normal period then 4 days later I had a slight bleed like old blood then I had nothing and again 2 days later started light again.
I had pain when it first started.
I have no idea what could be wrong...I have had the same partner for two years.
Should I worry?

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User623056 said on 07 December 2011

Hi - I finished the pill in January after taking it for approx 9 years.

My Periods are very stange I have a few days of very light bleeding, then brown discharge (dried blood), then start my period about a week later, fairly heavy for 5 days, its getting fustrating now, as it nearly every 21 days.

Do I have a problem? as I would like to start a family soon, does anyone know what it could be. I used to very regular on the pill and before I started the pill.

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User623056 said on 07 December 2011

Hi - I finished the pill in JAnuary after taking it for approx 9 years.

My Periods are very stange I have a few days of very light bleeding, then brown discharge (dried blood), then start my period about a week later, fairly heavy for 5 days, its getting fustrating now, as it nearly every 21 days.

Do I have a problem? as I would like to start a family soon, does anyone know what it could be. I used to very regular on the pill and before I started the pill.

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User614847 said on 10 November 2011

I am 23years old, on sept my period was a week late and my periods are always on time, on oct my period came a week early an only lasted one day an came back two days later and I notices i was having a lot of blood clots which lasted three days, now this month its came yesterday an now its gone again, do u think somthing wrong or is this normal?

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Taamie95 said on 10 November 2011

hi all, I'm 16 and I've had my period since I was 12, I went on the contraceptive pill for painful periods and it just made it worst so I went on The deporavera(needle) and for the last 3 years almost I've had non stop periods, been to doctors and had every blood test and nothing has come up I also had ultrasound and a gyno checkup nothing has come up.
I'd really like to know what's going on if anyone has any idea for me PLEASE HELP !?!

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jessicarrbrumm said on 30 October 2011

hi im 17, ive been on the implant for just over a year now it was fine when i first got it i had normal periods then i didnt come on for about 6 months, i then started having periods again but this time i was on for about 3 weeks on and off, i think i would come on almost every 2 weeks, and now ive been on for about 2 months on and off an my hormones are up the wall i am always constantly angry & when im not on i will have really bad period pains, i just need some advice on what to do, get it taken out or is it worth keeping it in?? :/

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Anonymous92 said on 28 August 2011

I am 19 years of age and have been without a period for 7 months now!! Last year i badly broke my foot and was on bed rest for 12 weeks and started tio put on weight after not being able to do my usual exercising... this year aswell i sprained my foot again and was out of exercising for a couple of weeks... my period stopped when id put on weight after i broke my foot first time. I had a healthy cycle before i gained weight, they were every 28-29 days and lasted for 5-6 days. will weight loss alone balance out my hormones again and bring back my period or are there any herbal tablets that can assist in bringing it back aswell? I have currently lost about 7lbs and am starting to feel slight cramps but currently still no period!
be great if you could help! x

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naarrnaa said on 24 July 2011

I am 16 and i can't remember a time when i didn't have irregular periods. I started my period when i was about12/13. There is always a different amount of time between periods and always last for a different amount of time. Sometimes i can be on my period for 2 to 3 weeks others 1 week, they are never 5 days or less. What can be the cause of this or what is it?

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tinykirsty said on 16 February 2011

hi im 23 years old i miscarried on 27 dec last year an i bleed for 2 weeks. one week ago i started spotting on an off 4 a week now i was wounding if that will normal thanks

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lesleyanne1977 said on 07 February 2011

am 34 had clips put on my tubes about 9 years ago since then i have had really heavy and painfull periods that totally exhaust me and am in bed sleeping for the forst 4 days i am in agony the whole week i have been to doctor many times but they dont listen

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Troz said on 21 January 2011

I'm 31, and have been on Microgynon for many years. I stopped taking the pill just over a month ago, and I'm already on my second period since stopping. The first one was 10 days earlier than I expected it to be, and my current one is 4 days early, but also much heavier. Is this anything to be concerned about

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clasmi said on 06 January 2011

I am 27 years old i came off the contraceptive pill marvelon last year in may and have had no period since. I had some blood tests at the GP which showed low hormone levels. The GP advised I return back in feb/march for further bloods, scan and for my husband to have semen tests. She then talked about referring me to the fertility clinic in may. We have been trying to concieve since august. I currently have period type abdominal cramps but still no period. I am getting increasingly worried I have PCOS, just waiting now until feb and taking a monthly pregnancy test as Gp advised.

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hermon said on 19 December 2010

i'm 28 and had been on the pill since i was 16 (my periods were like clockwork when i was on pill, once a month for 5 days) i came off the pill nearly 2 years ago as myself and my husband are hoping to start a family but my periods have returned very irregular (after the intitial 4 months when i had none at all after coming off the pill ) they have no pattern at all, they can be anything between 2 and 4 months apart and last for anything from 2 to 7 days, any ideas / advice? :(

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Ezz said on 26 November 2010

I am 16 and have had the implant in for a year and 3 months now. A few months after I got the implant I was on my period and since then it has stopped. Suddenly I get really bad pains and have come on my period. Can you tell me why it has came on randomly after not being on for so long because I am confused and hope for some answers.

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kirstyXXXX said on 19 July 2010

Hi im 16 years old and im always on my period every day! a year ago i started the depo contraseptiv injection, when i first started it i didnt have a period for 2 months.. about 2 months ago i told my nurse that i am always haveing a period and because my injection was a week later she said to me to have it done early to see if it stops my period YES it stoped it for about 3 days and then i carried on with a period and its now been 7 weeks that iv been having a period. i recently went to the doctors and told them everything what was happening and they didnt no what it was at all, and because a month ago i was giveing a clamida test they said for me to do that and then see what the results are and then make another appointment i got affended because i no i do not have this, im just really upset that they dont no what is wrong i feel its affecting me because i sometimes get so tiered and feel so sick. if you have any ideas what this could be or any adivise please tell me. thankyou x

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EllyBellz said on 08 June 2010

Hi, I've just turned 20 and about 4 months ago I was diagnosed with Glandular Fever. I was very ill and since then I have had irregular periods. I have been on the progesterone only pill for 6 months and was regular before I was ill. I had small periods every 2/3 weeks after the Glandular fever and then had one for over 4 weeks but not heavy. About a week after I had another light one and now have started again and it's been less than a week since the last one. Should I be worried?

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nicki4ads said on 05 April 2010

hiya i had a baby in november and have only had 1 period since, this is my 3rd child and have never been irreguler even after having my children could there be something wrong? i know im not pregnant as i havent has sex.

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Tina Marsh said on 05 April 2010

I keep track of my period using a <a href="">period calculator</a>. I put down the estimated future dates of my period and then I compare it to my actual dates to see how regular my periods are.

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Tina Marsh said on 05 April 2010

I keep track of my period using a <a href="">period calculator</a>. I put down the estimated future dates of my period and then I compare it to my actual dates to see how regular my periods are.

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EmilyyA said on 03 April 2010

I'm 16, at the beginning of the year I got glandular fever and my periods changed to every two weeks (I don't know why) the doctors put me onto a contraceptive pill and at the end of the month when my periods came I had lots of blood clots and was sick a lot, and it was two days longer than it should have been. I didn't go back onto the pill on Monday (when it finished) and then today it started again (today's Saturday) what should I do?

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EmmaFell said on 02 April 2010

I have been on the implant for 9 months now, my first two months were regular as normal then stopped for 7 months, then i came on for a week, then after another week ive come on again, is this normal???

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animal91 said on 18 March 2010

I am 18, I have been taking the mini pill for 6 months, i had a bit of break through bleeding in the beginning but then it stopped. For the past month or so I have had a small but noticeable amount of bleeding nearly every day. It lasts for 5 days then stops, but as soon as I have sex it starts again, I dont want to go to the doctors, does any one know what it could be, should I be worried?

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louu said on 09 March 2010

Im 16 nearly 17 and have had very irregualr periods.
I had my first period when i was 13 but then didn't have my next for another 6 months. 3 years on and they are still the same. i can go between 2 and four months without a period and now becoming sexually active it is now beginning to worry me. we always use contraception and nothing has ever happened to make me think i was pregnant but not having my period is very worring. Is this a really big promblem?

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rang said on 03 February 2010

hi i'm 22, i've irregular periods..and thats the first time i did get it for 4 months.....what can be the cause of it????It would be very grateful if someboby could help me or is there any treatment for it..

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zaqxsw said on 19 January 2010

i am 26,i have got irregular periods and dont know what to do. sometimes i dont get them for about 4 months. and sometimes i get little bit of bleeding and then just stops............ what might be a cause for it???? and is thr anything i can do to prevent this situation or are there any treatment for the same

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