another orgasm question

So I know we're all pretty tired of "was this an orgasm" questions, but I have to ask. Everyone says I'll know and even if it's not amazing it's really clear. So. Either I get off really easily with a vibrator or this isn't the real deal, BUT I get this intense warm feeling that builds until I get these contractions in my vagina that shake my legs and my body. It seems like an orgasm... it just goes on for longer than I would expect I guess. I thought it's supposed to be more of a release? Someone help. I'm so confused. I'm 23, I've been sexually active for eight years, and I just want this quest for the big O to finally end!