Even if you take letrozole for 5 days, you will not ovulate at this time. It is recommended to monitor the growth and development of the follicles by ultrasound to know when the dominant follicle is reached before the follicle ruptures and expels the egg. In the process of ovulation promotion, most of the ovulation will not be successful after 1 month of taking the medication, it takes about 3 months of ovulation promotion medication or about 6 months for the ovulation to be successful. When using ovulation medication to treat ovulation dysfunction, it is important to go to the hospital to monitor the growth and development of the follicles with ultrasound and to guide intercourse according to the growth and development of the follicles in order to improve the chances of pregnancy.