I think the primary focus of any eating plan for someone with PCOS is staying away from junk and processed foods, especially sweets.
You are really lucky to be one of the few who aren't faced with overweight issues.
I'm sure though that you can tell a big difference in how you feel if you eat sugar though, and I think everyone's goal in this situation is to feel good and energized- not necessarily to be a certain weight.
Have you heard of Yasmin? It might be a better birth control pill option for you as I've read it prevents the weight gain alot of healthy-weight women experience.
Good luck!