How can I tell if I have poor blood supply to my nose after rhinoplasty?

I've had two open rhinoplasty's. My revision is awful and it's too small. But, I'm worried about my blood supply to my nose. After my revision, my tip was a purple color for like a month or so. But, it faded every day and went away. My dr wasn't worried. But, I'm worried about getting short revision. Is there a way for me to check and see if my blood supply is ok? And I can handle a third surgery?