dislocated kneecap???

yesterday, right After I got into a bus, i felt my kneecap shift to the outside...it hurt like hell, but as soon as i straightened my leg, i felt my kneecap go back into place...now i cannot straighten out my knee,,,there is no swelling...what i wanna knw is i if my kneecap is dislocated or if it is something else...coz all my frnds are like its not tht, its a muscle catch, n tht dislocated kneecaps are very very serious
that had happened to me numerous times. I twist the wrong way and it pops out and when i stand back up it goes back in. I have loose kneecaps which is Why I get the popping so often. I also have had ACL and MCL injuries. But The doctor said that loose kneecaps can cause that, not usually the ACL and MCL. You probably have a build up of fluid around your knee to help cushion it more now, but that creats unbearable pressure sometimes. The best thing you can do is go to an orthopedic surgeon and get it checked out and possibly get some meds for the pain. Goodluck!