Blood coming from WHERE?? Nose?
It could be irritation from the carpet powder, if you used that.
Or it could be a fungus, or any number of things...try to find an open vet.
You could try a benadryl given at 1mg/lb of body weight - at 70lb. the dog could have THREE 25mg. tablets but check the dosage on the pills.
And I'd only do that if there were no open vets.