What Causes Bruise On Shin And Swollen Leg?

I fell a week ago and hit my shin on a steel cart. I bruise easy I have large and hard bruises on both shins one worst than the other. My left leg is still swollen and the bruise seems to be getting larger and its hard, Do I need to see a doctor?
Theirs heat in the bruise and little discomfort to the touch sometimes I feel a little burning.