Having intercourse on the day a woman ends her period can have certain negative effects because the period has just ended and there may be a small amount of residual blood in the woman’s cervix and vagina. During intercourse, it may lead to upward infection of bacteria in the vagina to the uterine cavity and uterine infection and pelvic inflammatory disease. During sexual intercourse, due to orgasm, the uterus contracts and there may be a small amount of endometrium peeling off in the uterine cavity and uterine bleeding may occur, which is not good for women’s health. It is best for women to have moderate intercourse only three days after their menstruation, after the vagina is completely free of blood and the cervical opening is completely tightened. Women should keep their vulva clean and hygienic before and after intercourse, and avoid high-risk behavior in order to benefit their health.