I had the same thing in my lungs and legs 6 years ago. I'm still on blood thinners and go to the dr. every 3 months. Each time I tell him I'm short of breath after walking a short distance or any exertion so went for more testing. Nothing wrong, but it's probably due to being overweight now. I'm working on losing the excess and have a long way to go.
Hope you are doing better every day....