Does Oral Sex Cause Pregnancy?

I had a girl over, we had been watching a movie, she was in her underwear, along with myself. She removed my underwear then began to give me oral, then proceeded to get on top of me where she let the head of my penis press against her vagina which was wet. I told her to stop because I did not have a condom. She got off, removed her underwear and put on the rest of her clothes. I do not believe I had any precum on my penis. Is this possible. An hour if not two earlier I had peed in a chlorinated in a pool (do not know if this helps). Thank you