Both short-acting contraceptives and emergency contraceptives may cause bleeding, mainly due to the following reasons: 1. In the case of short-acting contraceptives, the main component is a combination of estrogen and progestin, which can cause the common side effect of irregular vaginal bleeding after taking them. Once this phenomenon occurs, most of the bleeding will stop if you continue to take the pill. If the bleeding still cannot be stopped, symptomatic treatment, such as oral hemostatic drugs, can be used to stop the bleeding in most cases. 2. If you are taking emergency contraceptives, the main component of the emergency contraceptive pill is progestin, which will cause the endometrium to thicken abnormally and lead to withdrawal bleeding after stopping the pill. Regardless of the type of medication used for withdrawal bleeding, it is recommended to keep the vulva clean and change the sanitary napkin regularly. Most of the withdrawal bleeding after taking emergency contraceptive pills will clear up on its own in 3-5 days.