Sex on the first date?

I had sex on the first date. I knew him before and we had been talking for a bit. But for the first date We were a bit drunk, and it had been a while for me so I was ready haha. Anyway....we dated happily and amazingly for 3 years and are now engaged and TTC. It seems like a lot of people think sex on the first date ruins a relationship. What are everyone's thoughts?