The first thing you need to know about when it is not easy to get pregnant during intercourse is a concept called ovulation. If you usually have regular periods, you can calculate the time of your next period based on your menstrual cycle, and then subtract 14 days from that time to find ovulation. It is easy to get pregnant when you have sex at this time, 3 days before and after ovulation, a total of 7 days. The entire menstrual cycle minus these 7 days, the rest of the time is not easy to get pregnant, can be called a safe period. Of course, the safe period is also relative, there is no absolute safe period, because the ovulation period can sometimes change. If you have irregular periods, you can’t calculate the safe period or ovulation period based on this, and it is recommended to use contraception every time you have sex.