The delay in menstruation for 4 days may be clinically caused by the following reasons: first, pregnancy, if there is a normal sexual life, with contraception, first of all, to rule out the possibility of pregnancy, you can use the morning urine to do early pregnancy test, but also can draw blood for HCG test. In case of negative results, if you still haven’t had your period, you can do another early pregnancy test after 5 days. Secondly, endocrine disorders can cause delayed menstruation due to stressful work, tension and anxiety or environmental changes. It is suggested that this situation should not be nervous and can be observed for another three days. If there is still no menstruation, progesterone can be given orally to promote menstruation.