Cord falling off ; Normal??

My son will be one week old tomorrow. When I went to change his diaper I noticed a little spot on the front of his onesie (blood) and this is what it looked like underneath.

His cord is hanging on by a thread so I'm pretty sure the next diaper change it'll probably be off. (when he kicks his legs his diaper pulls the cord up more, yes I have the diaper folded down.)

is it normal for it to look like that after it falls off? his shirts and everything are sticking to it so I'm so scared once the cord is all the way off its gonna hurt him with everything sticking. I assumed once the cord fell off it would be a normal looking belly button.