Left leg pain, began in calf now behind knee and groin and back of leg. normal d dimer and leg ultrasound. what else could it be? haven't strained it.

Leg pain: Could be sciatica, Baker's cyst, synovial cyst , femoral acetabular impingement syndrome if athletic. or ilio-tibla band( though that is usually lateral pain) syndrome. Hernias usually cause groin/upper thigh pain but pain has unusual distributions. May also be from intracranial HTN. Discuss with you doctor, ask if NSAIDS/neurontin /lyrica may help if from nerve involvment..