If an emergency contraceptive pill is taken, the following hazards may occur clinically: the first one is that it may cause withdrawal bleeding after stopping the pill, about three days, which will clean up on its own; the second one is that it may cause menstrual disorders because someone is more sensitive. Thirdly, in clinical practice, people may experience nausea and vomiting when taking the emergency contraceptive pill; fourthly, in clinical practice, the emergency contraceptive pill may temporarily cause endocrine disorders because it inhibits ovulation. However the vast majority if just one emergency contraceptive pill may cause withdrawal bleeding and other symptoms may not appear. However, it is advisable to use condoms for contraception in daily life, after all, the side effects of the emergency contraceptive pill are still relatively large.