Many patients come to their imaging appointments hoping that the sooner the better, the better. In fact, there is a time to choose the time of the imaging. In our hospital, we usually choose 5 days after menstruation and before ovulation, and we also require no sexual intercourse and normal leukocyte test after menstruation. Because the endometrium is better repaired at this time, it is not easy for the contrast agent to enter the interstitial vessels (contrast agent entering the interstitial vessels increases the patient’s pain; increases the degree of contrast agent allergy; increases the chance of infection). At this time, the endometrium is not too thick before ovulation (too thick endometrium covers the mouth of the fallopian tube, so that the contrast agent cannot easily enter the fallopian tube, causing the illusion of proximal obstruction of the fallopian tube). At this time, the endometrium is proliferating, the interstitium is dense, and the epithelial cells are not easily shed (shed epithelial cells flow into the pelvis with the contrast medium, and if they are planted in the pelvis, endometriosis is formed, and endometriosis is also a factor of infertility). Of course, there are special patients who medically require imaging after ovulation, that is, patients with habitual abortion in the middle and late stages of pregnancy, to understand the function of the cervix.