I fell and hurt my pinky finger went to doctor and he said it was badly sprained it's close to a month now and i still can't bend it only half way ?

Go see an: Orthopaedic Surgeon. You need x-rays and an orthopaedic examination. This is to ensure there are no fractures, etc.

Tendon injury: you may have a tendon injury or a subtle fracture that was not seen initially. You need to have active physical therapy to improve your mobilization. Hand therapy is done by occupational therapists. Ask your physician to refer you to an occupational therapist or a hand specialist