there might be few other things going on than just sex.
Women get orgasms different ways. They can even have them just by touching them. I dont mean just down there.
Second thing might be for you, is that you dont know yourself so much. If you dont masturbate...and you think its wrong...then get over it atleast once...and do it. Play with it and see what happens. If you like porn...watch something what turns you on. Get to know yourself. And remember every moment if you play with yourself...how it feels...what comes next. Then when you are having sex...similar feelings may arise. Then you know what to do next..so you will get your orgasm.
Another thing is what goes on in your head. If you keep thinking and focusig "orgasm, orgasm, orgasm--when,when,when". Then you are not in the "zone" and it wont happen. Relax...dont think about anything else...just what you feel at the moment.
Another thing is that you are active side. Have sex like you want...do positions what you like and what feels really really good. And dont be shy to tell that. If he hits a spot, what really was good....then tell him straight away...that it was right spot, keep doing it. Same time relax...and dont think any thoughts. Just enjoy..
And women can have small orgasms too. It dont have to be huge always, so your eyes are rolling back of your head or so. No...there might be even small orgasms, so you will be thinking "was it orgasm? Because it was good feeling".
Just enjoy your sex and forget everything around you. Orgasms will happen, sooner or later. You need to "in zone" to get it.
Hope you got some advice
Cheers