What did i do to my knee?

Today i was playing football and i made a cut and my left knee make a couple cracks but nothing too serious. But now the outside of my knee is really sore. its a bit swollen and it hurts to walk a bit. I tore my ACL on my right knee and it feels a lot different as i remember. Last time i it happened i heard a "Pop" not cracks.but its making me a bit nervous. i know the ACL is on the inside of my knee and MCL is on the outside but im hoping its only a Strain.