I fell down the stairs at the local shopping centre?

i fell down stairs yesterday, there was only about 5 stairs but they were concrete ones i don't know if that changes anything, i had to ride my bike home after that so that probably didn't help but i sorta didnt use the foot i fell on, it has bruised and it feels sharp when i put any pressure on it. does anyone have a rough idea what i have done or what i should do?