football knee injury

I fell on my knee playing football and it immediatly swelled up on the inside part of my right knee just below the knee cap. It looked like i had a golfball stuck uner my skin. I had fallen on it a few times throughout the game and hadn't noticed anything until that one time. The funny thing is that it didn't really hurt that much. I could still play on it and I ran on it without pain. It has since been a week and the swelling went down a little but more so just spread out throughout the lower part of my knee. I can still walk and run with no pain but if I bump it or kneel on it at all it hurts quite a bit. I can see that there is a pretty good bruise on it bit I'm just a little worried about the swelling not going away fully. Anyone know if this could just be a bruised knee or is there something more serious going on here?