Answers appreciated

I just wanted to see if anyone can maybe tell me what an orgasm is exactly like I know but never had one maybe? When I masturbate, I have to really tense my legs and arms (on purpose) and then I get this quick 3 second feeling down there and that's it, I feel nothing else. When I try masturbating without tensing, it takes soooo long that I give up because nothing happens. Do you think that that's an orgasm?