I Fell Down 3-4 Steps This A.m. Not Sure How

I fell down 3-4 steps this a.m. Not sure how it happened, but I landed on my left shin against the wooden step. I managed to maneuver my leg out from under me while holding on to the railing, which prevented me from falling further down the steps. I now have a hard bump on the shin bone measuring about 3" x 2". I must have twisted my left foot which aggravated a previous break in the foot. Both the foot and the area of the bump are swollen. Both are moderately painful, especially when walking. Should I seek medical attention or give it a couple days?