Pulmonary Embolism Support Group
By far the most common form of pulmonary embolism is a thromboembolism, which occurs when a blood clot, generally a venous thrombus, becomes dislodged from its site of formation and embolizes to the arterial blood supply of one of the lungs. Symptoms may include difficulty breathing, pain during breathing, and more rarely circulatory instability and death.
is it possible for you to get a second opinion? This is what I did when I didn't feel satisfied or didn't trust what one hematologist was saying. I felt more comfortable and reassured by the second doctor, and he is the one I am sticking with. I strongly recommend you to do that as well, if possible, so that you can discuss all your doubts, etc.
How long were you on your BCP for at the time your clots were diagnosed? Why is your doctor convinced they accumulated over years? These are important points to discuss with your current specialist.
As far as testing is concerned, you can reliably be tested for clotting disorders while on thinners, but not for all of them. You can find more info here: http://emedicine.medscape.com/article/211039-workup
In the (unlikely) case that testing was incorrectly performed on you, I would suggest you to discuss with your doctor and eventually re-test. In my case, I had the blood-work done only after spproximately 1-2 months after I ended treatment with thinners, if I remember correctly.
I know how scary and anxiety-provoking is to get off blood thinners at first. I don't know if that can be of consolation, but at least now you know what a blood clot feels like and can likely recognize the symptoms before it is late. Keep an eye on yourself and, as I said, if possible get a second opinion.
Good luck!
A note on the testing - One thing that some people struggle with is that most people who get clots don't have a clotting disorder, and never learn the cause. It's worth asking the doctor if any of the tests should be repeated when (if?) you go off blood thinners, but it's most likely that you won't test positive for anything.
Most blood tests--especially the genetic ones--can be done while on warfarin, since your genes won't be affected by the medicine. The ones that might be better done while off warfarin tend to be Antithrombin Deficiency and Protein C and S. Double-check this with your doc as well.
Many (most?) people come off the thinners and do great. They don't reclot and they go on with their lives. BUT, it's definitely critical that you're comfortable with your treatment plan and with what you want to do. Write down your questions, ask your questions, and then regroup.