Anytime you have unprotected sex you take a chance of becoming pregnant. Sperm still escapes before ejaculation.
Oh goodness, no need to freak out just yet! The scenario you gave sounds like pregnancy would be highly unlikely, but I know your fear probably comes from hearing those one in a million chance stories of weird ways to get pregnant. So, unlikely that you're pregnant, but to be safe, watch to see what happens to your next period, if late, definitely take a test. I hope it works out for you! And perhaps think about a contraceptive, if you're open-minded to that, of sorts to prevent pregnancy in the furture so this doesn't happen again :). Good luck and best wishes.
Sara RN