From what I understand, you are a virgin if you have not engaged in penile penetration. Many people vary in their terms of virginity, but that's the one that we used to stick with (no pun intended). Oral sex is different to me, and practicing this doesn't mean you aren't a virgin in a certain aspect.
I guess it's all in the way you perceive it, and I perceive actual penetration to be a sign as to whether or not you are a virgin, or going "all the way".