I found out I have pcos and I have been on metformin. I have been seeing the pills whole in my stole. I am wondering if metformin stops working after a while? I had a period last month but nothing this month. I'm about two weeks late. I have taken a pregnancy test and its negative. I don't know what to do. My doctor says its just a fluke and to keep taking the pills. The pills hurt my stomach. I'm on the verge of giving up...