Is it normal that i can't tell when i orgasm?

Okay, so I've been masturbating for a long time and I thought I knew when I had finished. Like, it was just this feeling of having so much pleasure that you reach the breaking point and it feels amazing for 2 seconds and then it's over and I feel relieved. But then I lost my virginity and so far, I haven't gotten to completion with my boyfriend yet. I don't think. He fingered me once and swears that my vagina tightened up and he thinks I orgasmed, and it felt like I had. It's just hard to tell because I get really wet but it's not like a gush of fluid, you know? It just kinda becomes wetter. I just need to know if I'm overthinking it, and that when I feel relief, then I've orgasmed and that's that. I just want to to know. I don't wanna be insecure about it.