The majority of women cannot have an orgasm through intercourse alone (myself included). If you want to have an orgasm with intercourse, I would suggest masturbating during the act and get off before he does. For me, it intensifies and enhances sex even more, and I have even achieved intercourse orgasm this way!
You may have to watch pornography to get an orgasm. This may sound freaky, but maybe you and your boyfriend can watch porn together before having sex. I'm sure he likes watching it too. Hey, if it works, why not? It might improve your sex life.