How old were you when you had your first orgasm from sex?

I seem to be able to make myself orgasm easily through both clitoral stimulation and penetration (e.g. Fingers or anything else I use) but I haven't been able to orgasm during sex or foreplay with my boyfriend before. When he rubs my clit and eats me out it feels great but I never orgasm. Is this normal? Some people say that it's normal to not orgasm until you're older (I'm nearly 18 though), but is this the case or is it that he's just not getting me there?