Hi there,
I was on Metformin for 6 mths before starting Clomid. I was put on it because I have PCOS and am insulin resistant. Many girls with PCOS make more insulin then what is normal. Metformin normalises this. Weight is also related to insulin resistance and the heavier you are the higher your resistance levels can be. There is a blood test which can determin if you are insulin resistant or not. If you have not had one ask your Doctor for it as it will give you a definate answer.

I had the blood test and based on the results was put on Metformin. My Doc told me that it would help with weight loss (which it did) and the insulin resistance and basicly make Clomid more effective (I conceived on my 3rd cycle).

Im not sure how Metformin works if you do not have PCOS but a blood test can also determin if you do, a more accurate method is an ultrasound of your ovaries. I would say talk to your doc a bit more about it or seek more information. A good place for info is POSSA (Polycystic Ovarian Syndrome Ass. Australia) possa.asn.au - I found them to be a great source of information and assistance.

I hope this helps you a bit. All the best.
Poppy