A guy penetrated me for 5mins and didn't cum. The next day a guy ejaculated in me and im pregnant now. Who's most likely the dad?

Either one. Either one is possible, the second most likely because of larger quantity of sperm. BTW, sounds like you were TRYING to get pregnant, but no particular dad or spouse in mind. Is that your plan for a prosperous future for yourself & child (ren)? Do you have a trusted wise person to help you with THAT question? Please seek one out. Urgent! Hope that helps.