CONDOM BROKE

I was having sex with my friend and he finished inside of me. Afterwards, when he went to the bathroom to take it off, saw it had broke at some point and now we're both freaking out. He just left to get Plan B but according to my tracker, I'm currently in the middle of my fertile person. (But, it's usually off by a couple days so i'm not sure.) Does anyone have any recommendations? My friend is freaking out but I'm just looking for anything I could do to help prevent anything from happening (like pregnancy).