The great aunt is medically known as menstruation, and coitus is not allowed during menstruation. Menstruation is a special physiological period for women, when the pelvic and abdominal cavities are in a state of congestion and the body’s resistance is relatively low. At this time, coitus, especially unprotected sex, may lead to bacterial residue, through the open cervical opening to reach the endometrium, and may even enter the pelvic and abdominal cavity through the fallopian tubes, which may cause endometritis, adnexitis, or even pelvic inflammation and systemic infections, and long-term complications will cause chronic pelvic pain, and even and ectopic pregnancies, infertility, and the occurrence of the relationship. In addition to sexual intercourse during menstruation, due to the increase in pressure, it may lead to the reversal of menstrual blood flow, so there is a relationship with the occurrence of pelvic endometriosis. If you have already had intercourse during menstruation and are experiencing discomfort, it is recommended that you go to the hospital in time for a checkup and follow the doctor’s instructions for treatment and therapy.