Orgasm

This is a bit of a long post but I'm completely new to sex and everything sexual, lost my virginity to my boyfriend a couple months ago and bit embarrassed to say but I don't know when or if I have an orgasm I mean I feel a lot of pleasure and I end up shaking with pleasure but other than that that's it, I do get to a stage where I feel like I really need to pee and I usually panic and stop, is it at that point that you oragasm?

My boyfriend doesn't know that I'm unsure about whether or not I orgasm I'm too embarrassed to tell him because he always thinks I finish when I start shaking and I'm embarrassed to tell him that since the first time we've had sex I'm unsure if I've had orgasms because I don't exactly know what it feels like. Any tips or advice you have would be really appreciated :)