hello, There are several reasons of irregular period like PCOD, hormonal imbalance, over wt/ extreme loss, stress, emotional upset, eating disorder, thyroid problem etc. Therefore, you need one USG lower abdomen with PPBS, LH/FSH, Thyroid profile, Blood Progesterone for complete evaluation before changing to other medicine. Kindly, consult with your gynecologist and take advice accordingly. Combined hormonal pill is quite effective to treat irregular period. Control body wt, avoid stress, take healthy low carbohydrate diet with avoidance of fatty food and sleep properly. Be well.