I'm not condoning un protected sex in teens but really, telling these girls to 'check back in nine months' in un supported and frankly unnecessary.
I'm sorry to say but it really does sounds like you're pregnant, so when you're due your next period make sure that you take a pregnancy test.
If you are pregnant, then you have a pretty big decision to make, and it wwould be wise if you AND your partner make those decisions together.
If I were you, I would make sure you look into alternative forms of contraception regardless.
And please bare in mind that even if he pulls out, there is still premature ejaculation, where sperm can be released without the guy even noticing, so even if he had there would still be a chance of pregnancy
all the best hun.