I was on Clomid for 6 months, and took day 21 and day 28 tests to see if I was ovulating or not (I didnt at all for the 6 months even though is was up to a 250mg dose)

I was told the same as Alligatorsmum, if it hadnt worked within that 28day window then it would not be the clomid working it would be something else.

You sound like you are doing all the right things with your diet and exercise in addition to the metformin, so you may well be doing everything on your own.

Crossing my fingers for you that you get the results your after.