What is the cause of the sudden delay in menstruation

If the usual menstruation is very regular, suddenly this time delayed, first of all to see if there is no sex life, that is, first rule out the possibility of pregnancy, I am afraid it is the most common reason, that is, pregnancy. If ruled out pregnancy, menstruation did not come, it is necessary to pay attention to whether there is endocrine disorder, a variety of reasons, if affected the growth of follicles, affected ovulation, ovulation showed abnormal conditions, endocrine will show problems, also caused by menstrual performance problems. If it is determined that the delay is due to lack of ovulation, be aware of factors that may affect ovulation, such as staying up late, stress, anxiety, and fatigue.