Hi, A.. What a blessing to have two beautiful children aleady!! Congratulations!
I too have PCOS. My husband and I actually became pregnant on our own the first time but with our second child we had to result to in-vitro because of my PCOS. I have a good friend (who also has PCOS) and who was successful getting pregnant using Metformin and Clomid. It took them almost a full year and they were one month away from throwing in the towel.
I have VERY small hopes of getting pregnant again on our own too - my OB is almost certain it won't happen and that we should go through the infertility but I don't have it in me to do the in-vitro again. Personally, I'd rather adopt - due to my age (37) and my other health issues (clotting disorder and my history with gestational diabetes and PIH). But, I've been successful at dieting and losing some extra weight, I'm eating healthy and watching my stress levels. If it happens -WONDERFUL! We're going to start the adoption process anyway.
I think you're greatest advantage is that you are still young and have time. I know when family planning is involved - alot of families like to keep the children within a certain age range of each other for obvious reasons which makes it that much more stressful.
I don't know if this was a help but I did want to send you a message to let you know that going through infertility was one of the hardest things I've ever done and I have so much respect for others who have experienced some of the same things I have and still live to tell (and smile) about it!!! :)
I wish you all the best, A.. Send me back if you'd like. I'll be praying for your success, whatever your avenue to get there!
Take Care.
J.