Was it an orgasm?

I was having rough sex with a guy in his car.. It was amazing. It was like 10mins straight of just him pounding me. I've never had an orgasm. But all of a sudden i got this feeling like i was going to pee all over his car, so i made him stop. Was i about to orgasm or pee myself? How am can I be 21 years old and can't orgasm :(