Getting pregnant right before or after your period is unlikely but not impossible! Using the biological method of contraceptions is never the right choice and definitely not worth it if you are not planning to conceive. If you have sex without using contraception, you may get pregnant at any time during the cycle, even right before or after your period.
There is absolutely no ‘SAFE TIME’ for you to have sex without contraception at any time of the month and not become pregnant. There do exist some days where you are the least fertile but it does come with a risk of conception.
Now if the menstrual cycle is short, for example 22 days, you could ovulate just days after the period. The longest that sperm can survive in fertile cervical mucus is 5-7 days.So, it may just be possible for you to get pregnant if they ovulate a little earlier than usual.
BETTER SAFE THAN SORRY!