It is not normal for the endometrium to be 9mm thick after the onset of menstruation, but it is normal for the endometrium to be 9mm thick at the time of ovulation. Normally, there is no fixed standard for the thickness of the endometrial lining of a woman’s uterus, and it varies with the level of estrogen and progesterone in the body. Normally, a thickness of 8-12mm is normal during ovulation and 3-5mm at the end of the menstrual cycle, so a thickness of 9mm is normal during ovulation and abnormal at the end of the menstrual cycle. In case of abnormal endometrial thickness test results, it is recommended to consult a doctor to identify the cause of the disease and to provide targeted treatment or therapy.