I have polycst and i'm having my period for 2 months now with bad cramps. also, my period has bad odour. is this common and what caused this?

PCOS: Irregular periods are one of the most common problems obgyns treat. If this is one time problem it usually resolves on its own. If this is a recurring problem you should be evaluated. Infections & hormonal changes can cause spotting and a vaginal odor. If there is a concern for pregnancy then do a home pregnancy test . There are many options available to help regulate the menstrual cycle.