The main reason why the emergency contraceptive pill can achieve the effect of contraception in clinical practice is because of the following two mechanisms. First, the emergency contraceptive pill can inhibit the natural ovulation pattern of the ovaries, so that the egg will not be discharged and you will not get pregnant; second, the emergency contraceptive pill is a highly effective progestin, after taking it, it will lead to abnormal thickening of the endometrium and prevent the fertilized egg from being laid, so it will achieve the contraceptive effect. Therefore, the emergency contraceptive pill will have an inhibitory effect on ovulation, and some people are relatively sensitive to the emergency contraceptive pill, which will cause endocrine disorders and menstrual disorders because it breaks the natural ovulation pattern of the ovaries. Therefore, it is also recommended not to use the emergency contraceptive pill as a regular contraceptive method, but to use condoms and intrauterine devices for contraception.