Based on these tests the physician will determine if there is active follicle formation prior to ovulation. Evidence of active follicle formation includes a clear follicle of at least 12 mm and estradiol of at least 80 pg/ml. If the endometrium is at least 7 mm, ET will be scheduled. If the endometrium is less than 7 mm the patient will be invited for a second visit 1-3 days later.