Soreness under left shoulder blade and ribcage. had leg pain for over a month. negative ddimer, but could this still be a pulmonary embolism?

Ddimer is NOT 100%: Please know that a Negative D-Dimer is good test but is does not excluded a Pulmonary Embolism 100% of the time . Physicians who do not want to miss cases of acute pulmonary embolism when they clinically suspect the diagnosis should NOT rely solely on negative D-dimer assay results when the value to rule out the diagnosis is set at 500 ng/mL. A CT Pulmonary Angiogram may be indicated .

Maybe: Are you short of breath? This is almost always present with pulmonary embolism. A d-dimer does not absolutely rule out a pulmonary embolism (PE) and if the suspicion for PE is high enough, a chest CT should be performed. Also, because there are several other problems that may explain these symptoms, make an appointment to see your doctor soon.

D-Dimer,DVT overview: If your risk factors are low; Fam hx, birth control pills and likelihood of DVT are low, a negative D-dimer has excellent value in excluding DVT/thrombosis. Shoulder blade and rib cage symptoms may be musculoskeletal. For any symptoms of pain with taking a deep breath, shortness of breath with any chest discomfort should be evaluated. Leg recheck if still painful

Not likely: A normal (or negative) D-dimer means that it is very unlikely that you have any abnormal clotting. It's not 100% though. It may be worthwhile to have yourself checked out though. A simple ultrasound of the leg to rule out any deep vein thrombosis would be a good start.