Ugh, sorry about the condom failure. Which this is what it is. If he didn't ejaculate inside of you (it), that's better. But if he was unprotected inside of you, then that is a risk. It makes a difference where you were at in your cycle. It sounds like a chance but low odds. I'd not be overly worried. You can test 2.5 weeks after this happened to know for sure but try not to worry. good luck