Had 2 ultrasounds; left leg (hip to knee) to rule out DVT. Test normal. Now I'm having sharp pain/burning in upper and middle back can it be a clot?

DVT. Its good news that the ultrasounds were negative for deep vein thrombosis. More typically what we worry about is bits of clot breaking off and traveling to and lodging in the lung (pulmonary embolism). The presentation can vary...but this is mostly experienced as rapid onset of shortness of breath and chest pain. Pain in the back is not a typical presentation for a clot.