I hope one of your blood tests was the D-dimer. My SOB was misdiagnosed multiple times because SOB was the only symptom. Even an odometer was showing healthy oxygen levels. My pulmonary embolism was, instead of the usual clots, many tiny clots. D-dimer blood tests in the ER and then a CT scan with contrast showed the clots. Pradaxa twice a day worked a miracle. Probably will be on it forever but, so far, no bad side effects