Using NFP and withdrawal but had sex day before ovulation

Hey everyone,

I've been using this app to track my fertility to AVOID pregnancy, I'm 26 years old with 1 kid and in a committed relationship. Anyways, my boyfriend and i have been using NFP and withdrawal for about 3 months now with no hiccups and have been very careful to abstain during my fertile days BUT last night we had sex a couple times despite it being my fertile week and today is my ovulation day, i know i know stupid us! He pulled out every time and is very good at it so i know he didn't cum inside me but im wondering if i should still go and get a Plan B just in case. Thoughts?