Plan B ???

My husband and I didn’t plan to get pregnant until maybe 6 more months. But unfortunately today we had a slip up and had sex. I recently got off birth control maybe a month ago but I am a bit worried because I had realized that I was in my fertile window tomorrow dec.11 is basically my ovulation day. He didn’t come in me or even come close to and maybe it lasted 2-3 min before I stopped it to check the app. I really wouldn’t want to end up pregnant yet. Should I take a plan b?