I have been on coumadin (4mg) for 3 months after pulmonary embolism. 1 month prior to pulmonary embolism ,R leg ultrasound showed saphenous vein clot in upper thigh, no DVT noted. Both legs had ultrasound at hospital admittance with no saphenous vein clot or DVT. I ve noticed the re-curring symptoms developing in my R leg: heaviness and swelling. Could I still develop blood clots while on coumadin? Extremely compliant on coumadin and obesity is only other indicator (no cancer, clotting factors, no birth control pill, etc..) I suspect saphenous vein is involved. I had lympoma removed from same leg 4yrs (upper thigh in the crook of the leg and trunk). Could this cause a blood clot?