The contraceptive principle is to change the ovarian cycle to prevent or delay ovulation, and also to change the thickness of the endometrial lining to prevent the fertilized egg from being laid for the purpose of contraception. The emergency contraceptive pill is a remedial contraceptive method used to prevent unwanted pregnancy after unprotected sex or within a few hours or days after a contraceptive failure, and is only effective for one unprotected sex session, that is, for sex within 72 hours before the pill is used. The emergency contraceptive pill can cause a delay in ovulation because it can change the ovarian cycle, so if you have intercourse again after taking the pill and do not use contraception, then there is a possibility of pregnancy.