If you usually have a regular period, once a month, and you have a normal sex life, and your period has not come for more than half a month, you should first go to the hospital to check if you are pregnant, and if you are pregnant, an ultrasound will be able to detect it at this time. If you are sure that you are not pregnant, then it may be caused by endocrine disorder, first of all, you should go to the hospital to check sex hormone six and thyroid hormone, if there is any problem with these tests, then we should carry out treatment according to the test results. You must be careful not to work hard and stay up late, not to smoke, not to drink, to relax, to exercise, to keep a good mood to make the period normal.