Most Helpful Guy
I've experienced both, sex at the first date and sex after 3 months. Both resulted in a relationship that lasted a few years (the second is still going). If I could chose I would always chose to wait now. I don't regret it but I think it makes more sense to wait in the beginning. It makes the start of your relationship much more interesting and much more anticipating. Something you shouldn't miss out on. You can have enough sex later on.
Most Helpful Girl
If you're both comfortable with that and want to do it, then, sure, why not? :)