The pre-testing test may not always be done during the menstrual period, it needs to be decided based on the test. If the test is for sex hormones in the body, it needs to be done during the menstrual period. Checking the lining of the uterus and the condition of the follicles does not need to be done during menstruation. Sex hormone tests are usually done on the second or third day of menstruation, when the follicles in the ovaries have not yet developed, and blood tests can best reflect the basic state of the ovaries and are more accurate. Follicle development is monitored during non-menstrual periods. The first follicle test is usually around the tenth day of menstruation, and then depending on the size of the follicles, the next visit will be decided. Testing the lining of the uterus is best done one to two days before your period, when it is thickest. If the lining of the uterus is found to be thin, it is important to consider that there is a problem with the lining of the uterus.