Four weeks ago I fell down a few concrete steps and somehow landed on my right knee, scraping it; the fall happened so fast and I thought nothing of it(thinking back there may have been a pop when I fell). However, the next I had a dance competition at this point my knee was swollen and very unstable; though I still decided to dance on it all weekend. Most of the pain is located at the back of my knee. Now, four weeks later it hasn't gotten better. I thought that maybe I had pulled something, but should it last this long? I mean I know I am dancing around 5 days a week, but I've been taking it easy. Today walking up and down stairs I now noticed pain at the top of my kneecap, but most of the pain again is behind my knee. It's usually not an excruciating pain, but it is like a dull ache. And another thing, I'm not sure if this makes sense... But when I straighten my knee (I usually have hyperextended knees) or bend it past 90 degrees it feels as if my knee needs to pop or is going to snap. And today my knee actually gave out. Should I be worried or go in to see someone? Thank you for reading this, and let me know what you think. Let me know if you have any other questions :)