Fell off my bike, scraped my knee pretty badly?

Did I sprain my knee or just tore a muscle? Please read all.?

• Please read all if you can: I was playing volleyball in mid July for 2 weeks at a camp, but on the second week i hurt my knee after jumping for a spike. I heard like this weird cracking/ popping noise then fell to the floor. The pain was soo immense, and it didn't go away for a good 2 minutes. My knee area was real sensitive after that and so my doctor gave me an immobilizer. Two weeks later i was able to walk a little better so i bought a new knee brace that was smaller w/ metal rods. My knee's been healing pretty slowly (or maybe I'm just impatient) but I've been able to jog and bike ride and do all the stuff. The only movement I was limited to doing was kneel fully with my butt touching the soles of my feet. I was able to stretch my leg fully straight though. But then yesterday, i was playign some light volleyball again at the park, but when i went to simply throw the ball, with my left leg forward (thats the knee that's injured), it 'popped' again and I fell on the floor in pain. The pain didn't last as long this second time, but it did hurt for about 20 seconds. I limped to a nearby bench and it started swelling up. Now I'm stuck here with a swollen knee, filled with liquid. Now I cant bend my knee back at all, but i can still stretch it straight out. What's confusing to me is that my actual knee doesnt hurt, the muscles at the back of my thy hurts, as well as the top part of my calves. My knee only hurts when it's bent. But i can knock on it and hit it and stuff like that. So what's wrong with my leg? Is it really a knee sprain? Because my knee doesn't really hurt unless it's bent. The muscles around it are actually what caused my pain after the accidents. And did I resprain it that second time? Does the healing process have to start back from square one? And if i DID sprain my knee, do you think it's a moderate sprain or severe sprain? My volleyball season starts around november, do you think I can play by then? Thanks for taking the ime to read this!

• Answer:

  you'd better go to hospital to make sure it.