After taking the pill, most of them will have withdrawal bleeding in about 3-5 days after stopping the pill. This kind of withdrawal bleeding is relatively small and will clean up on its own in about 3-5 days, mainly caused by the side effects of the pill. When the pill is stopped, the endometrium will lose the support of exogenous progesterone and will have withdrawal bleeding, which is the main side effect of the pill. However, not all people experience withdrawal bleeding after taking the pill, mainly because if taken orally during the first half of the menstrual period, withdrawal bleeding will occur. If the emergency contraceptive pill is taken orally during the second half of the menstrual period, retreating bleeding does not always occur clinically, but it does not indicate contraceptive failure clinically.