Thank you for your query.
Looking into your problem i would like to tell you that polycystic ovaries
are a known cause for irregular and scanty menses. Losing weight , exercising regularly and dietary modifications are helpful in treatment of this disease.
I advise you to consult a gynaecologist , she might consider to put you on oral contraceptive pills
having anti androgenic effects to regularise the menstrual cycle.
Hope you are satisfied with the answer.
If you have any further queries feel free to ask.
Wish you good health.