Suggest Treatment For Pain In The Knees And Calf Muscles

Question: Hello. I am having back of knee and calf pain. mild to moderate but consistent. the calf pain has been gradual and a few days, the behind knee pain for a few weeks now. I get nervous about clots, however I have already been twice to the ER, once a few months ago the other a few weeks ago and no DVT found in either chest or leg ultrasounds. That's why I am hesitant about going now because they never find anything, despite higher D Dimer readings in blood tests taken on 3 occasions over the last several months. I should add I might have lumbar radiculopathy and suffered herniated disc in lumbar region last October 2016 and my disc generative disease has worsened in cervical and lumbar regions we found in nMRIs. My question is should I still go to ER and could it be clot they didn't catch the first 2 times or could it be a popliteus muscle really tight and try not worry an focus on my PT like both my massage therapists tell me???? I did the at home check and no redness, no lump, no swelling in one leg over the other (however both legs are out of shape and I am a bit overweight), not hot to the tough or too cold. The only issue I have is my knee makes clicking sound now and I have pain and achiness behind knee and recently calf down to ankle. I had a cardio stress treadmill test this week and everything was normal and Dr said it looked good and my BP is good at 119/70 if that helps.