If a normal person mistakenly takes the emergency contraceptive pill, it will cause the following clinical harm: First, the emergency contraceptive pill is a high-efficiency progestin, after taking it, it will make the endometrium abnormally deep, and then after stopping the pill, the abnormally thickened endometrium loses the support of exogenous progesterone, and there will be a retreating hemorrhage, thus leading to vaginal bleeding for 3-5 days, but the amount will be relatively small. Secondly, it can cause ovarian ovulation dysfunction, because high potency progesterone mainly inhibits ovarian ovulation, so in the clinic, it will break the law of natural ovulation of ovary, and may cause endocrine disorders, which will lead to menstrual disorders or irregular vaginal bleeding in the clinic; in serious cases, it will also cause liver and kidney function damage.