Having intercourse once near the end of menstruation may have adverse effects on the body, which may easily lead to abdominal pain, heavier bleeding, susceptibility to infection, and may aggravate endometriosis and other pathologies. Having intercourse near the end of menstruation, so when the cervix is still slightly open and there is menstrual blood discharge, if you do not pay attention to sexual hygiene when you have intercourse, it is likely that external bacteria will be brought into the vagina. Since menstrual blood is a breeding ground for bacteria, it is more likely to lead to bacterial reproduction and cause vaginal inflammation, endometritis, pelvic inflammatory disease and other diseases may occur. In addition, infection of the female uterus can easily cause abnormal proliferation of the endometrium, which can easily induce endometriosis in women. In addition, because the male penis can secrete prostate fluid, it will also contain prostaglandins. Prostaglandins stimulate the uterus, causing it to contract abnormally, leading to increased abdominal pain and menstrual bleeding. Therefore, it is not recommended to have sex when menstruation is coming to an end, and if there is abdominal pain or abnormal vaginal bleeding, it is recommended to go to the hospital as soon as possible and follow the doctor’s instructions.