The oral emergency contraceptive pill is still effective within 48 hours, and as long as it does not exceed 72 hours, the pill will play a contraceptive role. The contraceptive principle of the pill is to inhibit the secretion of the glands of the cervical canal, which will become more viscous and prevent the entry of sperm, thus playing a contraceptive effect. The success rate of the emergency contraceptive pill is around 80%, with a 20% chance of failure. The pill can cause some adverse reactions, such as withdrawal bleeding after taking the pill, which depends on each individual’s body type. If you experience a delayed period while taking the pill, it is recommended that you take an early pregnancy test to rule out the possibility of pregnancy.