Protected sex on fertile window

Please give me reassurance!!

So last night I was not looking to have sex at all.. but we started kissing which lead to you know what. I always get nervous about being pregnant.. and that’s why we barely have sex because I don’t want that risk. Anyways, I am fertile.. but we used a condom. And it seemed to be okay? Please tell me if I’m okay and just over thinking it? Why does being a girl suck at times like this. Someone please be a big sister here❤️😩