What is the safe period of menstruation? The safe period of menstruation refers to the time period in a woman’s menstrual cycle when it is not easy to get pregnant. During a woman’s menstrual cycle, ovulation is the time when pregnancy is most likely to occur. Outside of the ovulation period, the female reproductive system is in a relatively safe state. Therefore, it is not easy for women to get pregnant if they have sex during the safe period of menstruation. However, the safe period of menstruation is not a 100% safe contraceptive method, and you still need to pay attention to contraception. How to Calculate the Safe Period of Menstruation