Most women take estradiol for about 21 days to get their period. Estradiol is an estrogenic drug that can promote the thickening of the endometrium. If a woman does not have a period because the endometrium is too thin, she can take estradiol, and when she takes estradiol for the last 10 days, she needs to take progesterone, and then she will have a period only after she stops taking progesterone and estradiol together. If an ultrasound examination is done and adhesions are found inside the uterine cavity, such women may not have menstrual flow even after taking estradiol. Therefore, an ultrasound examination must be done before taking estradiol, preferably a 3D ultrasound examination to rule out the possibility of uterine cavity adhesions.