On the second day of a woman’s menstrual period, how big the follicle is normal varies according to each person’s own situation, generally the second day of menstruation belongs to the sinus follicular phase, the follicle is relatively small, less than ten millimeters in diameter. The size of a normal follicle is about 2-6mm. follicular development from the beginning of the follicle to the primary follicle development changes, follicles more than 2mm in the speed of growth, you can go to the hospital obstetrics and gynecology department for ultrasound to observe its growth and development process. If a woman’s ovaries are not functioning properly, the level of sex hormones may be abnormal, which may affect the normal development of the follicles. The normal number of sinus follicles is 5-7, too few may be due to poor ovarian reserve and too many may be due to polycystic ovaries. The size of follicles in different periods of time is different standards, in the follicular development of girls should pay attention to the body’s diet and sleep and rest, regulate the diet, eat more phytoestrogen-rich foods, such as soybeans, black beans, papaya, etc., so as to make their own physical condition better, more conducive to the normal development of follicles.