condom broke

Me and my boyfriend were having sex and he stopped and told me the condom broke. I’m not on birth control because this is only the second time we have had sex. He told me that I had nothing to worry about because I made him cum earlier, so there was nothing there to get me pregnant, but Im still nervous because can’t you get pregnant off precum? He said there was nothing but I’m still a little nervous. If I take plan B tomorrow morning should I be good or should I still be worried?