Am I having an orgasm???

So my boyfriend goes down on me frequently and I almost always have a clitoral orgasm that way with no issues. (Same with when I masturbate) however up until I met him, the sex that I had was never really satisfying for me so I had never had a vaginal orgasm during sex. Now with my bf, i get to a point of very very intense internal feelings, but I don't know if this is an orgasm or not. Like since it doesn't feel the same as clitoral stimulation I can't tell if it's really the "climax" or he's just hitting it really good at that particular moment 😂 he does say that my vaginal walls will tense up really tight and sometimes he'll pull out and I'll see some white discharge on his dick. Could that be just discharge, or actual female ejaculate?? Does it sound like I am reaching orgasm? I'm pretty clueless on this so I appreciate any help!