You can have a 3-hour GTT (glucose-tolerance-test) drawn - specifying insulin levels - to determine if you're IR. I'm overweight, but that's d/t a drastic change in activity level without a change in diet (I had a major injury that impacts what activities I can safely participate in), and was showing minor IR with "great" blood sugars.
After the 3-hour GTT w/insulin, you can see if you're IR or not - if not, there may be no benefit to met... but if you ARE IR, then your MD should put you on met - even if not for the purpose of TTC - untreated IR can lead to diabetes and other serious negative health outcomes.
I say this to everyone, because I have worked in healthcare and am HORRIFIED by what I have seen: YOU HAVE TO BE AN ADVOCATE FOR YOUR OWN HEALTHCARE!!! If your doctor won't do the blood test, go to someone else who will - you are a CONSUMER of healthcare - tell the medical community what you want by spending your healthcare $$ where you are getting what you want! You wouldn't order the world's best sushi and be okay when the waiter says, "No, you can't have sushi, I'll bring you tilapia." You'd go elsewhere, right?! Same thing with medicine!
Okay... off my soapbox and to bed with my tired brain!