Weight gain with irregular delayed menses may be one of the signs of PCOS. A metabolic disorder which can be very well controlled by healthy and frequent small meals and regualar exercises. After consultation with a gynecologist you can safely start with hormonal
pill, that would regualarise your menstrual cycle and also control other problems like pain in menses, anemia
, premenstrual symptoms, obesity, acne and hair growth if any. It would also help in contraception
if you are not planning pregnancy
immidiately after your marriage. Usually you will not have any problem in getting pregnant.