Hello, If you are sexually active, you must undergo one home pregnancy test to rule out pregnancy at the earliest. In this context, most common cause is ovarian cyst/ PCOD, hypothyroid state, obesity, pelvic infection, stress/ depression, hormonal imbalance, high prolactin etc. Kindly consult with gynecologist for clinical examination and relevant investigation like USG scan, thyroid profile, blood sugar/ prolactin, LH/ FSH etc. It helps to pinpoint the diagnosis. Hormonal medication is the treatment of choice. Take low carbohydrate diet, do regular moderate exercise to control body wt. Avoid mental stress. Good luck.