Ddmer test slightly elevated, no blood clot in lungs from ct scan. in the clear, or need to keep an eye on it?

Healthy concern: With a negative CT, I would hope that you are in the clear; however, I would have a healthy concern and monitor your breathing and symptoms.

Yes, assuming: no other explanations for your presumed chest pain an/or shortness of breath, ie lung or heart issues, would monitor your symptoms and adhere/continue recommendations from your local doc.

Non-specific: A Slightly elevated D dimer is nonspecific. A negative CT scan with contrast virtually excludes pulmonary embolus as a major cause of the elevated d-dimer. You may need a follow up d-dimer to ensure resolution. If the D dimer remains elevated your general practitioner need to do a battery of tests to determine the reason for the elevated d-dimer.