Orgasm....

So I'm 18 and I've never had an orgasm, like my mom and sister always ask me if I had one and I tell them yeah so they leave me alone but I've never had one, I mean if I did I think I would know right? I cum when I have sex but I never orgasm, is it me? Or the guy? Or both of us?!!! I want to experience one so badly, but I feel like guys only care about getting their nut off