It depends on what time the bleeding occurs. If the bleeding occurs when your period is almost clean, because the amount of menstrual blood is relatively small, the front and back walls of the vagina are closed, and a small amount of residual blood will not flow out, and there may be no blood on the sanitary napkin. When you go to the toilet, urinate or defecate, the vaginal wall is squeezed through the thin posterior fornix, squeezing out the residual blood inside, and there will be blood when you wipe it with paper after going to the toilet, which is a normal phenomenon, don’t worry about it too much. In the menstrual period just clean, in fact, do gynecological examination there will be a small amount of menstrual blood, so it is recommended to be sure to menstrual period clean 3-7 days before intercourse, so as to avoid the mouth of the uterus is not completely closed resulting in infection, but also to avoid due to the blood sinus is not completely closed, sexual stimulation leading to rupture of the marginal blood vessels, the vagina again a small amount of bleeding may occur. If it is during the ovulation period, a small amount can be observed. If it occurs after coitus, it is recommended to go to the hospital to check the cervix.