How soon can a 12 year old girl have her period after she has leucorrhea? Generally, if a 12-year-old child has leucorrhea, she should have her period soon, because the time for women to have their period is usually around 11-13 years old, the puberty development of girls is in this period, the child’s sexual organs are more mature, ovarian function is also gradually mature, can establish a normal ovulation cycle, at this time the ovaries can secrete estrogen and progesterone, you can have your period. The situation of menstruation is also related to the hormones secreted by the thalamus and pituitary gland, generally soon after the leucorrhea will have menstruation, if it lasts longer than about 14 years old and still no menstruation, you can promptly go to the hospital to do gynecological ultrasound to see the development of ovarian function, and if necessary, you can also do a sex hormone test to see if the child has disorders of sex hormones.