@lune: I understand that your Doctor doesn't want you to do Clomid for more than 3 months. It is known that Clomid thins the uterine lining.
@anmlz: doubtful with the success on metformin. My OBGYN put me on it because she said she had seen great success with it, my RE took me off it because I am not insulin resistant and he said they don't have long term studies on metformin and diet (less sugar, more protein) and metformin have the same effect unless you're insulin resistant, that's a different story then!
Actually you should google protein and IVF success. There is some interesting stuff out there!