The pain in the abdomen after intercourse during menstruation is due to the excitement of the uterine lining during intercourse, which causes uterine contractions and accelerates menstrual cramps. And the fallopian tubes and the uterine cavity are connected, menstrual blood reflux will be through the fallopian tubes to reach the pelvic cavity, will also cause pain in the abdomen. Therefore, it is not recommended to have coitus during menstruation, because there is a chance of cross-infection, which can also cause salpingitis, pelvic inflammatory disease and even endometritis, which will have a certain impact on the future of pregnancy, and the increase in the amount of bleeding will accelerate the shedding of the uterine lining, resulting in more than one menstrual flow. At this time, you can take oral antibiotics, such as cephalosporin or amoxicillin, oral 3-5 days, first for the prevention of infection, if more than 7 days has not stopped bleeding, is the need to stop bleeding medication, otherwise it will affect the body’s health.