The reason why menstruation has not yet come may be the following: First, consider the habitual late menstruation, because different women, the menstrual cycle and the duration of menstruation is a time gap, not everyone’s time is the same, as long as it is in line with the law, that is, the habitual late menstruation, the menstrual cycle and the duration of menstruation is relatively fixed, which is normal. Second, consider suffering from gynecological inflammation, normal menstruation can not be produced without the vagina, uterus, ovaries, if any of these organs have problems, can lead to late menstruation, or even no menstruation, common situation is suffering from endometritis, ovarianitis, vaginitis, etc., can lead to late menstruation. Third, the female endocrine system is impaired, because the formation of menstruation is greatly related to the level of hormones in the body, and if there are problems with the endocrine system, it can also lead to late menstruation.