Hello. Im Quite Worried Right Now. My Boyfriend And I

Hello. Im quite worried right now. My boyfriend and I have not participated in any form of sexual intercourse, however our genitals have come in contact with one another. This has only happened once, and he pre-ejaculated a little bit while doing so (more towards the upper portion of my clitoris and pubic area). The last time he ejaculated was two days prior to the incident, and urinated multiple times. As soon as we saw the precum i was able to wipe it off. I was just wondering, what are the odds of me becoming pregnant? (I am on no form of birth control)