There is no pregnancy and the period is late. First of all, we have to look at the delayed days, under normal circumstances, menstruation is normal within a week in advance of the wrong time. More than seven days without coming, once in a while is not a big problem, generally like tension, stress, staying up late, weight loss also make menstrual disorders. Some people take birth control pills can also cause delayed menstruation, so there is no pregnancy, menstruation does not come, within a week can be observed, more than a week of special concern can go to the hospital to do an ultrasound, look at the thickness of the lining, determine the approximate time of menstruation, occasionally this time can be observed. If you are particularly worried, you can use the right medicine according to the thickness of the endometrium after the examination. In general, in this case, if you are nervous or stressed, you can use such medicines as prozac and motherwort pellets to regulate the situation, or if the lining is thin, you can use progesterone. If the lining is thin, progesterone for ten days, after stopping the drug will also come to menstruation. Therefore, you can observe it once in a while, but if it is often not allowed, you must do the relevant examination. The endocrine test is usually done for menstrual disorders, and according to the results of the test, the symptoms will be treated.