What are the chances of having a false negative d dimer? i had 2 negative ones in december within 2 weeks of each other

Low: Normal d-dimer result means that it is most likely that the person tested does not have an acute condition or disease causing abnormal clot formation and breakdown. Most doctors agree that negative d-dimer is most valid and useful when the test is done on people who are considered to be at low to intermediate risk for thrombosis. The test is used to help rule out clotting as cause of symptoms.