Condoms, IUDs, the pill, tubal ligation, vasectomy...<quoted text>
At what time during the course of human history, did sex between men and women, STOP resulting in conception? That hasn't changed. We still do it, still understand what it does, still need for it to happen. That's the one constant? Men and women married each other. There are TWO sexes.
Sex isn't just for reproduction. We like it and we like it with the partner of our selection, whether that be like or opposite sex. That hasn't changed either.