Pcos and irregular periods

Was diagnosed with pcos by a fertility specialist a few years ago after 4 years of ttc and nothing. I would go years without periods. Recently went to gyn he peracribed my prometrium. 2 weeks on two weeks off. After 5 days of taking it I started to bleed... really bad. Big clots. I am no in off weeks. Haven't taken it in two days. Day 11 of period and still just as heavy as day one. Any suggestions on what todo? Tough it out? I feel like I'm bleeding to death!