About 2 Weeks Ago, Upon Waking Up, I Noticed That

About 2 weeks ago, upon waking up, I noticed that my right ankle and calve were quite swollen and somewhat discoloured, with tinged of blue closer to the ankle and tinged of yellow in the leg. Not really painful, just progressive feeling of heaviness in that leg. I saw my dr. the following day(day 2) and had a d dimmer test done stat which came back high(682). My dr. recommended I go to ER. ASAP. They gave me an injection in my stomach to prevent further clots, as they suspected DVT and PE. They did an ultrasound of my leg as well as CT scan of my chest on the 3rd day. Both test came back normal. By then, the swelling had started coming down. They sent me home with no explanation or answers as to why the sudden swelling. Everything went back to normal within the next few days. Now, 2 weeks later, the same thing is starting again. Only this time, along with some blue and yellow tinges throughput the leg, my ankle stay white when standing and when pushing in various spots with my finger on that foot and leg, the skin remains white and doesn't go' back to its pinkish color like normal. I'm not really worried that it could be too serious, but would like to get some answers. Any ideas??

PS. Not sure if this is relevant, anyhow, I was diagnosed with fibromyalgia 2 years ago, after 3 years of unexplained widespread pain and multiple testing from specialist. The symptoms started shortly after an unknown insect bite. I suspected lymes disease, because I had 95% of the symptoms, although I didn't have the typical bulleye rash. My dr. ordered the only test available in Canada and I've since been told by many that the test is not accurate, at least not like the ones available in the US.