Before the menstrual period is not completely finished before intercourse is not pregnant, because at this time the cervical mouth is still in the open state, and the vaginal flora imbalance, the vaginal environment is relatively poor, if this time intercourse is very easy to let the bacteria invasion, serious will cause the upward infection, and may even cause pelvic inflammatory disease. Because the cervix is in a state of congestion during the menstrual period, if you have sex before the menstrual period is not completely clean, it is also easy to cause gynecological diseases, such as endometriosis. A few days after menstruation is a safe period, when the follicle is developing, the chance of pregnancy is not great, but not completely without the possibility of pregnancy, if you have intercourse after menstruation is clean, you still need to do a good job of contraception. If you have intercourse after your period has not cleared, you must pay attention to it and go to the hospital promptly if you have a dribbling period or an infection.