Please help!!!

My boyfriend and I were having protected sex when we changed positions I was able to hear the condom break and tell him to stop. He did not get a full pump in and we stopped sex immediately. He did not ejaculate before we started sex and I went swimming 2hours after the event. I had just gotten off my period, however I am now roughly 1-2 days late on my next period. Is there any chance his pre-cum could've gotten me pregnant? I am underage and a 4.0 GPA student athlete, so now is not the time for a baby. If this is the case that I am pregnant... what do I do? Any advice would help. Thank you so much.