Withdrawal bleeding usually occurs when vaginal bleeding occurs around day 3-7 after treatment of amenorrhea or irregular periods, or after taking the oral emergency contraceptive pill, and is medically known as withdrawal bleeding. When there is no withdrawal bleeding, it does not mean that it is a good or bad thing, it is just a normal phenomenon. The lack of withdrawal bleeding may be caused by a thin endometrium or pregnancy. When a woman’s body is low in estrogen, it can cause the endometrium to be thin, resulting in no withdrawal bleeding, or it can be caused by an insufficient amount of progestational estrogen. In addition, we cannot rule out the possibility of women taking the emergency contraceptive pill and having no withdrawal bleeding as a result of contraceptive failure. It is recommended that when there is no withdrawal bleeding, you should go to the hospital in time for examination, such as blood tests for human chorionic gonadotropin and ultrasound to understand the thickness of the endometrium and the presence of pregnancy in the uterine cavity, and to clarify the medical history before treating the problem.