Why is my dog afraid of the smell of human blood?

Your dog does not think that you smell tasty and is not scared that you are declaring your territory. Dogs know what blood is. They know that it is a sign of injury. She is upset because you have an injury and she doesn't know what it is. My 3 dogs will not leave me alone if I am bleeding (I am remodeling my house and it happens often believe me) but maybe your dog is scared by the blood because she isn't used to it... like my dogs unfortunately are. Just stop blowing in her face and ure her that you are indeed fine.