I'm sorry to hear what you are going through with your dog but it sounds like you are taking all the right steps to finding out why her nose is bleeding.
we have a 12 year old that was just diagnosed with nasal cancer this past October but bleeding was not something we noticed and while I know it can be a symptom of cancer, it can also be a symptom of so many other things so I hope the CT scan helps you figure out what is going on.
We don't have a CT scanner here in Winnipeg for dogs so we had an endoscope done where they put a camera in her mouth and looked back into the sinus cavity. They also took a biopsy from the roof of her mouth into the mass and that is how we got our diagnosis.
I hope you find out it is something minor. Try not to worry, I know it is hard but if it makes you feel any better, although our dog has nasal cancer, it is a very rare cancer for dogs to get.
Did your blood testing include tick disease? Some tick diseases can cause nose bleeds as well. (We also experienced this with our dog a few years ago).
I hope you get good news tomorrow.