Talk to Gynecologist on Irregular Periods

im 30, weight 4 years back.. have never conceived yet. my periods r irregular since i turned 13. gap between 2 cycles are on average 3 to 6 months. have cyst in left ovary and suspected to pcos.. recently having no treatment.. reason for writing this post is this, "i had periods dor almost 1 month in ramzan.. it stopped, then it started again after a month for 9 days(light brown spotting and not at all heavy). it stopped.. now after a week and a half it started again... whats the reason? kindly tell me the reason for what this is happening