you have what is calles postphlebitic syndrome, once a clot is present it damages the valves and produces chronic reflux unfortunately for life, dvt involved your femoral vein, not your femoral artery
ultrasound is the definite test for dvt but if you have a dvt in the iliac veins (larger veins) ultrasound is non diagnostic and you have to undergo more complex tests like ct venogram that few radiologists can interpret right
once you are anticoagulated usually with an oral agent that thins your blood within 3-4 hrs we assume that you might be safe from a pulmonary embolus which is a fatal outcome.
in general unless there is thrombophilia (tendency to clot) i assume that my patients are safe to fly as long as they dont drink alcohol, hydrate themselves and ambulate in the airplane every 2 hrs with compression stockings within 2 weeks of the onset, but the time is debatable and you will find many different opinions