Metformin reviews?

My husband and I have been trying to convince baby #3 for the past 7 almost 8 months with nothing but BFNs. A couple months ago my dr prescribed me Clomid and after 3 months, nothing... I went to see her today for a check up and she said everything looks good and healthy but isnt sure why I haven't gotten pregnant yet so she prescribed me Metformin. I have done a little research on it but I wanted to know if anyone had success with it or had any issues. I was so excited about starting Clomid that I just started taking it and it made me incredibly sick and have excruciating cramps. I want to see others experiences with it.