If your period is normally normal and you suddenly experience a delay in menstruation, it is important to rule out pregnancy if you are of childbearing age and have a normal sexual life without using contraception. If pregnancy is the cause, it may lead to menopause. If you are not pregnant, most of these cases are caused by endocrine disorders, such as recent stress or sudden emotional shock, or environmental changes, such as moving from a relatively warm city to a relatively cold place, which may cause abnormal menstrual cycle in the near future. In most cases, menstruation will occur 3-7 days after stopping the medication. In addition, if you still do not have your period after stopping the medication, you must rule out the possibility of ovarian failure.