orgasming

So I'm 16 me and my boyfriend of 8 months have been having sex for a little over 6 months, and it's amazing but I never orgasm and once in a while I'll get kind of close but I can never orgasm and I know it makes him feel like shit but I really don't care, but it'd be nice to. Idk if it's cause we haven't been having sex for that long (he was having sex for like a year before me so he knows what he's doing). The sex is really good (and leaves me shaking sometimes) but I never orgasm. Help?