The coitus is a normal physiological activity, so the vast majority of the coitus will not appear after the reaction, even within three days there will not be any reaction, only the vaginal secretion increased, mainly caused by semen ejaculation into the vagina, most of the semen will be discharged out of the vagina. It is recommended to keep the vulva clean after coitus. Washing the vulva after coitus is mainly to avoid reproductive tract infection. If you don’t pay attention to hygiene during coitus, you may experience inflammation three days later, such as increased vaginal discharge, yellow color or odor, which is caused by inflammation of the vagina, or itching of the vulva, and it is recommended that you actively use medication to treat it. If there is a history of high-risk sex and gonococcal infection, the leukorrhea will be like pus and accompanied by frequent urination, urinary urgency and other symptoms. For other STDs, there will be no reaction after three days of intercourse.