What Causes Pain And Swelling In Chest Obstructing The Subclavian Vein?

I was told by a Dr several years ago that there may be a chance I have lupus but another Dr said it was extremely unlikely and not worth doing any further tests. At this point I had had terrible chest pain and swelling intermittently for 2-3 years and a DVT in my R leg. I have factor v leiden and was put on warfarin. I have had two ANA tests done, one was moderately elevated and the other highly elevated. My D dimer has been positive on at least five occasions. Once a lupus anticoag cam back low positive, the other time negative. I have chest pain still and when it swells it is obstructing my subclavian vein. I also suffer with knee pain in both legs, more on rest, relieved my movement. I am tired frequently also. I have no rash. I do get exaggerated swelling to insect bites. I have seen a cardiologist because the GP wanted to check my chest pain wasnt cardiac but now I have been forgotten in the whole primary care system! ( I live in England) Can you shed any light on all this for me? Thank you for your time.