I think it all depends on the person.
There really isn't any reason why two people shouldn't be able to have sex on the 1st or 2nd date, if you are feeling horny, attracted to the person, then why not?
Society has taught us that sex is something more then it really is. Reality check ladies, its only what you make of it.
Sure, chicks are scared that they will have sex with a dude and he's gonna blow her off shortly after. But reality check here, if he's gonna do that on the 1st date, he'll do it on the 10th date. So you are doing yourself a favore by figuring shit out sooner rather then later.
The fact is, most relationships DO NOT work out. You will ended up dating FAR more people then you actually have a real relationship with, let alone marry. Sex is part of dating, its part of getting to know someone, its part of figuring out compatibility and chemistry.
Sure you want to get to know someone before being completely intimate with someone, so I'm not saying skip the conversation and get straight to the fucking, but jesus, don't be so uptight about it. Its only pussy, not some holy kingdom.