You should not have intercourse before your period is over because the cervix is slightly open when you have your period. If you have sex at this time, it is easy to bring pathogenic bacteria from outside the body into the vagina, which can then infect the uterine cavity through the slightly open cervical canal. The presence of bacteria can lead to endometritis. Bacteria can also infect the pelvic cavity through the fallopian tubes on both sides, causing acute pelvic inflammatory disease. The actual fact that women are less resistant during the menstrual period and the pelvic organs are more congested, it is easy to cause the spread of inflammation, which is detrimental to women’s health, so you should not have intercourse when your period is not clean.