What Causes Burning Sensation And Severe Pain In The Leg?

Hello, I have been having odd sensations in my left leg for about two weeks. I returned from an overseas trip and the symptoms started about 3 days after the return plane trip. My first thought was a bloodclot, so I went to my dr and she did an d-dimer test. It was below 0.5 (normal range) and she suggested ibuprophen and keeping it elevated when possible, thinking there was just inflammation. It has been another week, and now there are warm/cold sensations in my calf. Still some pain behind my knee. I can feel my pulse in the leg. Should I go back to the doctor for another test?