NH,
It might be better if the guys jump in here.
But just to give a quick reply, this is basically how it started out for all of us, I think. "Not a UTI."
However, there are other reasons for blood in the urine, which you will probably be tested for and will be ruled out first. My first test was for kidney stones.
I am not at all sure how Coumadin would play in to this, but it is an interesting question.
I hope that things work out well for you. We are here if you need us.
Take good care,
Rosemary