Question on Metformin Dosage

I went to my OBGYN a few of weeks ago, and they said they thought I had PCOS. So they decided to start me on Metformin 500mg, start 1 pill a day for a week, then go up to 2 pills/day the second week, etc. Til I reached taking 4 pills/ 2000mg a day. I been researching online, and I haven't really found that many people that was put on such a high dose of Metformin. What is your experience with Metformin? MD said if I'm not pregnant in 3 months, they are putting me on Clomid.