I guess it depends on the situation. I won't let myself feel pressured to have sex nor deny myself if I want it over #'s. My bf and I have been together close to 2 years and we had sex on our 3rd date.
I feel awful about this (kind of as we hate each other now), but my college sweetheart was with me for 1 1/2 years...waiting. I split up with him and lost my virginity a couple of weeks later. He was pissed but we got back together after a while. I ended up actually sleeping with him a year after the initial breakup. That's the longest I've ever waited.