Hello,
First of all it can be due to metrorrhagia which causes
uterine bleeding at irregular intervals, particularly between the expected menstrual periods. Metrorrhagia can occur due to dysfunction uterine bleeding, hormonal imbalance, polyps, fibroids, endometriosis, infections of the cervix, vagina or endometrium, pelvic inflammatory disease, ovarian insufficiency, ovarian cysts or benign lesions of the female reproductive system.