congratulations, you're normal!

Most women don't and/or can't orgasm from intercourse alone, not even if he's like gribble and can last for hours (though that technique is definitely still worth a shot; maybe you're lucky and are actually able to come from just intercourse, just takes a little more endurance?). To orgasm from intercourse you probably need either additional clitoral stim, or a guy who knows where the g-spot is and what to do with it. Supposedly g-spot orgasms come easier for women who have already given birth, though.