Hello, Thanks for posting on HCM, The causes of irregular periods (with metrorrhagia or vaginal bleeding between expected periods) are numerous and some of them are reversible conditions. Some of the causes are: - Hormonal imbalance: for some known or unknown reasons, female reproductive hormones maybe be secreted abnormally in blood, hence resulting to menstrual irregularity. - Endometriosis: abnormal thickening of uterine wall and ovaries can lead to this condition - PCOS: condition in which a woman has an imbalance of a female sex hormones. This may lead to menstrual cycle changes, cysts in the ovaries, trouble getting pregnant, and other health changes. - Uterine fibroids: symptomatic forms may lead to irregular periods - Pregnancy: complication of pregnancy or abnormal insertion can lead to this - Uterine tumors: cancers if present could also lead to this. - drug-induced Given that this situation maybe delicate, it will be best if you booked an appointment with a gynobs as soon as possible. The doctor will be able to examine you, run some tests including an pelvic scan which may be able to detect the exact cause of your problem and may subsequently provide you with treatment. Hope this helps