Monitoring of the follicles should be done from day 9-10 of the menstrual cycle, a process that allows you to see the entire follicle growth and development, and allows you to see the emergence of the dominant follicle to the maturation of the follicle to ovulation, which is the entire process. The size of the follicle is observed on day 9-10 of the menstrual cycle and then every other day or so until the appearance of the dominant follicle is seen. For the dominant follicle, monitor every other day. The dominant follicle grows at about 2mm per day, and the follicle is mature when it reaches 18-24mm. For mature follicles, ovulation must be observed to be a complete follicular monitoring process. Mature follicle ovulation is manifested on ultrasound as the collapse of the original follicular dark area, a decrease in tension, and an irregular liquid dark area, or follicular fluid, can be seen in the pelvis.