Deep Vein Thrombosis (DVT) Support Group
Deep-vein thrombosis, also known as deep-venous thrombosis or DVT, is the formation of a blood clot ("thrombus") in a deep vein. It can be caused by something preventing blood from circulating or clotting normally. Join the support group if you are coping with DVT and find others who are going through the same challenges.

I didn't see a hemo until after my second DVT. At that point, they discovered that the original clot was still there (but it wasn't causing any problems, so not a worry) and they did run a full blood panel. I was negative, so no help there.
There are other threads on this group about whether a final ultrasound is necessary before getting off warfarin. I don't think it is necessarily necessary. Many of us don't have them because not all clots dissolve so what would an additional scan show? Some docs do use them to decide when to take you off warfarin (they WANT the clots to go away), but it doesn't happen for everyone.
Also, with a clear "cause" like BC, most docs won't look further for other causes and run expensive genetic tests. They didn't test me until it was obvious that clotting was a repeat problem and they wanted answers. With your additional health issues, I don't know if testing makes more sense after only one clot. It is a good question for a hemo but many, many people don't get the genetic tests after only one clotting episode...especially if there seems to be a clear cause.
Hang in there ... read some of the other posts on this site ... and don't be afraid to ask the docs questions!
Good luck with your treatment!
A doppler scan of the affected leg, as well as a follow-on chest CT for chronic PE, is appropriate as well before any decision to continue or quit Warfarin.
Being in USA, I was able to get all those tests. I dread what is coming with impending bureaucratcare, in which "civil servants" become the arbiters over people's lives. Maybe I won't live to see the worst of it.