See, this is where another set of variables comes into play, and the way I've come to halt the problem of not knowing whether you can pull her on the first date has a few parts to it, both before and during the date, but time to explain...
Before I establish the date, in the initial approach and pull, I've got her thinking about sex with me, girls respond well to my sexual frames, so, I know before the date takes place that I can bed them on the first date. That is what you'll want to do, gauge her level of sexual interest early on.
If, you still are unsure about whether you can bed her on the first date, you can ramp up the kino, I generally look for every excuse or opportunity to physically touch one another, and, play around with the kino. If she sits next to you, work your hand up to her inner thigh, if she doesn't resist, or if she smiles, you can pull her that night. BTW, inner thigh isn't the only kino test, but for me, its a sure fire gauge...
If, after all that, you think you still can't pull her that night (and she was willing to go home with you), then she'll start to reject further plans unless you make them quickly, or she'll put you in the boyfriend or lover category, and will slow down sleeping with you. General rule of thumb is if you don't bed her on date 1, you'll have to on date 2 (if you're only looking for sex, not a relationship), or you'll lose almost all opportunities to bed her.
However, if you are looking for a relationship with her, you can take your time bedding her, you can bed her fast, or slow, your choice. Generally, when I think a girl is girlfriend material, I'll bed her on date 3 or 4.
But, in all honesty, kino for me isn't even that necessary to pull, it helps a lot, but I can pull without it. I use a lot of sexually suggestive frames in a teasing way, and girls jump all over it, that's my favorite gauge of interest because I naturally tease anyway.
But overall, if you don't feel you can pull her that night, you might still want to try while the momentum is good. Try sexual frames on the date, and try nonchalantly mentioning plans after the date to see where her head is. Still try to pull her though, and if you don't, kiss or hug her that night, and text later to keep the momentum rolling...
-Hope this helped,
Richard