I had taken once every couple of hour photos of the deloid muscle in the left upper arm where the injection went in (B-Pfizer shot 1). Easy to do when you are always fiddling with your smart phone. After about six hours there was a red welt around the tiny plaster and pain the muscle. It went away the next day. However, there was itch on the back the next day that lasted a whole day, and I had to use a bamboo back scratcher to scratch it. A photo of that showed reddish scratch marks !! Now it has been a few days, and all is well. Take photos after the 2nd shot. Don't fear the 2nd shot. You had already released the RNA into your body, and the booster isn't going to do anything new.