Yes, although it is not very likely. If you have sex without using contraception, you can conceive (get pregnant) at any time during your menstrual cycle, even during, or just after, your period.
You can also get pregnant even if you have never had a period before, during your first period, or after the first time you have sex.
There is no 'safe' time of the month when you can have sex without contraception, and not risk becoming pregnant. However, there are times during your menstrual cycle when you are at your most fertile, and this when you are most likely to conceive.
Understanding your menstrual cycle
Your menstrual cycle begins on the first day of your period and continues up to the first day of your next period. You are most fertile at the time of ovulation, (when an egg is released from your ovaries) which usually occurs 12-14 days before your next period starts. This is the time of the month when you are most likely to get pregnant.
It is unlikely you will get pregnant just after your period, although it can happen. It is important to remember that sperm can sometimes survive in the body for up to seven days after you have sex. This means that it may be possible to get pregnant soon after your period finishes if you ovulate early, especially if you have a naturally short menstrual cycle.
You should always use contraception when you have sex if you do not want to become pregnant.