Are you on blood thinners?
I have a hard time believing that The Mayo Clinic wouldn't be one of the very best places around for treatment. It makes me think that--as usual--there's more to the story. The body is such an amazing but complicated system and a cancer diagnosis seems to change everything...including how your blood clots.
My husband went through a battery of tests to identify why he had clots (in the lung and legs). They needed to find out if it was "just" the cancer or if there were genetic reasons for clotting.
I need to be careful about getting out of the "information sharing/support" mode and talking about highly specific medical conditions.
I suppose what I feel most fortunate about is having a doctor whom I trust completely, who also is an articulate and caring person.
Stay strong. Try to stay relaxed and engaged in life. Don't be afraid to ask questions.