What Causes Pain In Hip After An Injury?

I fell down a flight of stairs 10 days ago, hitting my hip on each stair ...back left side just above my buttocks. I have an inflamed area there with what seems like a dent...and the pain is worsening. The bruising was SEVERE, but isn't as "bright" now...but pain is worse. Its excruciating if I turn my body to get out of my car. I see my doctor this afternoon but am researching ahead of time. Your thoughts? (please and thank you) :)