Generally speaking, if you have intercourse during a safe period or during your period, you are less likely to get pregnant, but it is not recommended to use safe period contraception alone. Normally, intercourse during menstruation is not recommended because of the risk of gynecological infections or endometriosis. Normally, the menstrual cycle can be divided into the menstrual period, the safety period and the ovulation period, which is usually about 14 days before the next menstrual period. The safe period is generally divided into the pre-ovulatory safe period and the post-ovulatory safe period. If your period is regular, that is, from seven days before your period to eight days after your period, it is less likely that you will get pregnant during the safe period. However, it is not completely certain, because the body’s endocrine system is not completely stable and there are cases of early or delayed ovulation. Therefore, for those who want to prevent pregnancy, it is recommended to use condoms or contraceptive pills or to place a birth control ring, and to seek medical advice in case of delayed menstruation to check whether you are pregnant.