Tegan, sorry to confuse. PCOS needs to have a number of symptoms in order to get the diagnosis. A single bloodtest cannot provide this. You really do need an internal u/s of the ovaries to see the 'string of pearls' appearance, although in a small percentage of women the ovaries do appear normal. BUT... there needs to be a number of symptoms all together, that's why PCOS is a 'syndrome'. My first diagnosis was from an OB/GYN who 'diagnosed' on the basis of a single bloodtest, so he should have known better (hence your GP also should have, so don't assume that the GP really is knowledgeable enough on PCOS, actually most don't know much about it at all).

I'm not saying you don't have PCOS. After all, I had all the extra tests done and I was confirmed as having PCOS. But there is a possibility that you don't have PCOS. Metformin can have some really nasty side effects (gastric), so you'd want to be sure that it might help you before you took it. I'd seek a second opinion from a doc who really does deal with PCOS a fair bit, if I were in your shoes.