The presence of menstrual flow just after sexual intercourse does not exclude the possibility of infection, as the presence of pathogens such as bacteria, viruses, fungi and other infections during sexual intercourse can invade the female vulva as well as the vagina. If the couple is in good health and has a strong immune system, and if they take effective hygiene during sex, the probability of infection will be reduced, or even not. It should be noted that before the onset of menstruation, try to avoid sexual intercourse to avoid causing infection.