I need help!

had a slip up! guy thrusted maybe 4-5 times during my fertile period (22%).. he didn't come close to ejaculating.. didn't nut inside of me at all and I know that for a fact.. I took plan b 1-2 hours afterwards.. what could be my chances that I end up pregnant? I'm so stressed about this. . 6 days away from my period and I took a test today... it was negative...