Kind of a TMI about anal but I need help!

So my boyfriend and I decided to try anal last night. Kind of just spur of the moment. We got it in a little bit but eventually it hurt too bad so we stopped and just resumed having vaginal sex. After while I turned around so we could do doggy style and he said, "um babe, I think you have poop on you." So I turned around and sure enough, it was on me and him and the bed. I wa so embarrassed! We cleaned up and finished having sex and everything but I feel so terrible about it. He didn't seem to mind. He even said, "Hun, I'm a plumber. I'm used to having that on me." Which didn't make me feel any better about it. He didn't really seem grossed out but I still feel bad. Has this happened to anyone else and does anyone have any tips for me?