As long as there is no blood in the vagina, the chance of infection during intercourse will be very small. However, patients should pay attention to contraception at this time. It is not recommended to use methods such as in vitro ejaculation or emergency contraceptive pills, but to use condoms. The use of condoms after menstruation can not only prevent unwanted pregnancy, but also play a role in cleaning and isolating the vagina, as the vaginal resistance is low due to the decrease in the number of vaginal bacteria and the destruction of vaginal acidity after the vaginal flushing of blood.