An early period may occur during puberty and perimenopause due to hormonal changes. Other possible causes of bleeding before a period is due include endometriosis, polycystic ovary syndrome (PCOS ...

A period is considered “early” if menstrual bleeding begins within 21 days of the beginning of your previous period, according to Monte Swarup, M.D., an OB-GYN in Chandler, Arizona and founder ...

Age-related hormonal changes, like puberty and perimenopause, may also cause early periods. Most people get worried if their period is late or they miss a period, but an early period can be just ...