Should I be concerned?🤰🏻

Y’all I am freaking out and need advice please! So I had sex with my bf about 10 hrs ago and we didn’t use protection and I’m not on birth control (that’s a whole other story). He finished in me on accident and I’m scared I may get pregnant. My fertile window begins in 4 days and if the app is right then I begin ovulating 8/28. But… I got off my birth control a few months ago and my most recent period (8/14-19) is the first period I got in 47 days (which has never happened to me). Anyways, I took a Plan B 10hrs after butttt I am also obese so the chances of its effectiveness goes down. Should I be worried about pregnancy or am I thinking too much into it?!