My knees hurt when i run/exercisee?

When i run my knees(sometimes one, sometimes both) start aching. They hurt ad after i am limping when i walk. I play field hockey and lacrosse. And ski and snowboard in the winter. I run almost 4 times a week. Im a 14 year old girl and im about 5 3ish. Should i see a docter for those knee brace things or whatt? Thankss!