I have PCOS too, and when I saw Dr Lolatgis -- the resident gyno of BellyBelly. He told me the biggest mistake the doctors made in my last 2 pregnancies, was insisting I stop taking the Metformin once I was pregnant. In the first pregnancy, I stopped at the start and miscarried early at 6-8 weeks. In the second pregnancy I was advised to take the metformin till 12 weeks, and then stop. My daughter was stillborn at 20 weeks. Looks like things start to go wrong about 6 - 8 weeks after I stop taking metformin.
Dr Lolatgis, also told me to keep taking the metformin and don't stop taking it for the rest of my life. Metformin has been a miracle drug for my severe PCOS symptoms. It really is the best drug for PCOS, and believe me, I have tried everything and it was the only thing that worked.