Knee Injury?

Last night I was goofing off with a friend of mine and I had wrapped my leg around theirs, but when I quickly unwrapped it and went to stand up my leg buckled and I fell. The medial side of my knee hurts now but it is stable with no sign of injury (minus some pain) and I can walk. I have it wrapped up and iced now but I don’t want to have to go get an MRI/Xray unless I need to(you know you that can cost). Did I sprain it or worse, tear my MCL?