2 ultrasounds in a week 3 ddimers of 307. Dr says no dvt. I still have leg pain after 2 weeks. What are chances it's still a clot? Worried.

Needs further eval. D-dimer is a very non specific blood test. A negative d-dimer and a negative venous ultrasound rule out DVT . Your leg pain does not seem to go along with a DVT especially with 2 normal ultrasounds. Since the d-dimer can be elevated for many reasons , a ct of the iliac and proximal femoral veins would complete your evaluation and definitively make or rule out the diagnosis.
Low chance . No all dvt's will be seen on ultrasound, not all elevated d-dimers mean dvt. And leg pain can be caused by many other things besides dvt. In this instance our doctor will consider the pre-test probability (your risk factors) for for presence of dvt. Very unlikely this is DVT with two negative ultrasounds. Venography can be considered depending on risk factors.