5 Days Ago I Came Down Hard On My Right

5 days ago I came down hard on my right knee (onto cement)and had extreme pain for an instant. Today I tried to kneel on that knee and I had so much pain I fell to my stomach. I can walk fine and it has only felt like a deep bruise except for the initial injury and today when I tried to kneel.
I'm also a 54 year old female if you need that info.
Please tell me your thoughts?