Not sure it makes you stronger, but it depends on the couple. I had sex the first day I MET my guy and we've been together over a year and lived together most of the relationship (he moved into my house 2 months after we met which was the day we started dating). I've never had a stronger or better relationship than this one. I waited almost a full year before having sex with my ex husband, and he was the worst mistake I've ever made! So that's an example of where waiting vs non-waiting do the opposite, but that doesn't apply to everyone.