How do I know if I had an orgasm?

I had sex last night and it was really great. Our emotions were high, our cuddling was perfect, even the sex was somehow more in sync. There wasn't any problems, but I don't know if I orgasmed. I have ejaculated before (it's been a while since then and I miss it) so I know what that feels like and I didn't. I felt very calm and content afterwards. I didn't feel excited or euphoric, just content. There wasn't an exact moment where I felt like "this is it, I'm at my climax" either. My boyfriend has told me that girls have different types of orgasms and one of them is a prolonged feeling rather than a sudden climax. Is that true? Did I maybe experience that? I'm sorry for being unknowledgeable but I've only had one partner and he only had one before me so we're not the most experienced. Thanks!