Brown blood on day 5 of intercourse is not necessarily pregnancy. In the menstrual cycle, vaginal bleeding means different things at different times. If intercourse is about 14 days before menstruation, the vaginal bleeding may be ovulatory bleeding. If it is in the premenstrual period, it could be an upcoming period, or if the period heals before it arrives, it could be pregnancy or menstruation. It may also be bleeding caused by endometrial polyps or cervical erosion. When black blood is flowing during intercourse, do not have sex for the time being and it is better to go to the hospital for consultation. If it is about 14 days before menstruation and there is not much vaginal bleeding, you can observe it temporarily. If it is on the eve of menstruation, you can observe it temporarily. If the period is delayed, you can go to the pharmacy to buy early pregnancy test paper to first rule out pregnancy. Taking emergency contraceptives may also cause withdrawal bleeding, if it is caused by drugs, don’t worry too much.