I've Been Diagnosed With A Left Pulmonary Embolism. I've Had

I've been diagnosed with a left pulmonary embolism. I've had CT scans and echo done. However they are just watching it every once in a while I experience shortness of breath . I am on high blood pressure medicine and I take one aspirin a day is there something else that should be done. I was also told that if I start to cough up blood go directly to a ER. To me it sounds like they are waiting for something to happen rather than being proactive