Asking my Doctor

I am almost 16 - yes, I know that's young. But, I am interested in talking to my doctor about starting birth control. I am in a serious relationship and have been dating my boyfriend (of the same age) for over a year. We are both doing well academically and are extremely responsible/mature. We've even sat down with both of our mothers at the same time to discuss birth control methods etc. My boyfriend and I don't plan on sex for at least a few months but we want to be prepared and I would like to get comfortable with whichever method I choose beforehand. 
Anyway, I have a physical tomorrow and I was wondering if anyone has tips on how I can ask my doctor. For example, what to say and how it might go?