If you want to do follicle monitoring, it usually starts from the 10th day of menstruation, that is, from the first day of vaginal bleeding to the 10th day of follicle monitoring. Nowadays, the most accurate and commonly used method is to monitor the follicles with ultrasound. The size of a mature follicle is usually 18-20mm, which is the mature follicle, and the follicle will ovulate after maturity. The follicles grow at a rate of about 2mm per day and the doctor will recommend when the next ovulation test will be based on the size of the follicles seen at the first ultrasound. If he sees the follicles and they are close to maturity or mature, he will instruct intercourse. At this point, if you have intercourse, you will be more likely to conceive, which means you have a higher chance of conceiving with intercourse.