Orgasm buildup?

I’ve never orgasmed before or even felt like I’ve been close. However, there was one time when I was with a guy who had a pretty huge dick and he was just pounding into me pretty quickly. I started to feel some pressure and kind of sore, so I told him to slow down. I’m not sure if that’s what the buildup for the orgasm is supposed to feel like or he was just going to hard. What is the buildup to an orgasm SUPPOSED to feel like?