Orgasm?

Ok.. so I have a stupid question here. How do you feel when an orgasm is coming? I know that many will say “you just know”. But I really want to hear some other thoughts.

I’ve been sexually active for 2 years with my bf - feels good, but never orgasmed. And I also never orgasmed by touching myself.

I bought a little vibrator and after using it for some time (TMI) it feels like it’s starting to pulse really hard down there for a few second and then everything goes away. I don’t know if this is a beginning of an orgasm or ... 😅

Anyone? I’m loosing hope