If the endometrium is 1.4 cm thick when you reach your menstrual period and you do not have a period, consider the following: First, consider the possibility that you will have a period soon, because the endometrium can reach 1.4 cm before you have a period. The second is the possibility of pregnancy. This situation should be combined with the specific situation, if there is a sexual life without good contraception, must focus on screening to see if it is pregnant. You can take a urine pregnancy test, or you can go to the hospital to check the blood progesterone or human chorionic gonadotropin. Thirdly, it is important to consider whether there is abnormal hyperplasia of the endometrium, endometrial lesions. In this case, an ultrasound review should be done after menstruation. Usually the endometrium should be thin at this time, and if it is around 0.2-0.3 cm, endometrial lesions can be excluded.