It may be possible but it's odd you didn't have pain when it happened. When I tore my ACL it was the worst pain I have ever experienced. There really is no true way to tell unless you have it examined by a doc.

I kinda know what your going through and i have that same question mines alittle different though. I went to an independant exam this last tuesday and during the exam he wanted to measure my knees.. my left one naturally hyper extends my right use to before a recent car accident anyways he forced my right knee (the injuried one) to hyper extend i told him it hurt so he stopped but i noticed that night my knee was pretty swollen and since then its felt like i'm walking on knife blades. like you said it hurts to walk or move my leg in certain directions and it is also uncomfy to sit in any position for more then a few seconds i have to constantly move and its always a sharp pain. My knee cap also shifts it hurts pretty badly

Its not a torn ACL. It may be tendonitis of the quadricep or patella or maybe a bit of damaged cartilidge that has become inflammed. I think it should go away