I Have Banged My Leg Just Under The Knee On

i have banged my leg just under the knee on the outside. it has turned very black and blue it is very painful,,,it has swollen up quite badly i have tried ice and a dr saw it at the emerg. at that time it was not yet black but it was quite swollen out at the top of the leg. just wondering what is the best to take care of the pain and swelling??