Orally transfered pre-*** pregnancy!?

Last night i masturbated, then went to bed. This morning i woke up, took a piss, and went to school. My girlfriend came home with me. She gave me oral sex, I pre-came only, we then kissed, and I then ate her out. She was ovulating and she is not on birth control. What are the chances of pre-*** sperm that weren't expelled from my piss earlier in the day, got in her mouth, then into mine, then into her vagina causing pregnancy? Bottomline - Could she be pregnant?