Retreat bleeding after taking the emergency contraceptive pill is mainly caused by the side effects of the drug, because the emergency contraceptive pill is a highly effective progestin, after taking it, it will cause the endometrium to thicken abnormally. The amount of withdrawal bleeding is not much, much less than the amount of menstruation, and most of the bleeding will be clean after about 2-3 days, and the bleeding is dark red, and will not cause symptoms such as lower abdominal pain. In the event of withdrawal bleeding, don’t be nervous, keep the vulva clean, strengthen local care, and change sanitary napkins regularly to reduce the possibility of infection.