The difference between follicular atrophy and discharge lies in the presence or absence of pelvic fluid, changes in follicular size, changes in basal body temperature, and changes in the character of vaginal discharge. 1. Pelvic fluid and follicle size: After the follicle discharges the egg, ultrasound can see the original follicle disappear and pelvic fluid appear. In the case of follicular atrophy, the original follicle can be seen to become smaller, but still exists, and no pelvic effusion will occur. 2. Changes in basal body temperature: When a follicle discharges an egg, the basal body temperature will rise. If the follicle shrinks, the basal body temperature will not change significantly. 3. Changes in vaginal secretion: When the follicle discharges the egg, the vaginal secretion will decrease and become thicker. In the case of follicular atrophy, there is usually no change in vaginal discharge. By monitoring the follicles through ultrasound, it can be clearly seen whether the follicles are discharged or atrophied, if the follicles discharge eggs, you can arrange for coitus to increase the chances of pregnancy.