Question: Been having pretty significant knee pain for a week. Recieved a cortisone shot yesterday as my MRI is not scheduled for another week. Feeling much better today. Do I still need to do the MRI? Will receiving that cortisone shot interfere with the MRI results?

Cortisone shot made me feel like a new person the next day and so I decided to go for a walk thinking light exercise might do me good. Beforethe shot I could not bend my knee without pain. After the shot no pain at all. Now since my walk I cannot straighten my knee and i feel like if I step to hard orthe wrong way my knee may give out. Walking was no problem before shot. I still do not have much pain...maybe bc of the shot. My initial pain came from twisting my knee. I felt something pop at that point but nothing started to hurt until several days later. My MRI is Monday. Just wondering if I might hve done something else during my walk or since the shot took away the pain, i am now realizing a sensation of instability? Anything I should do prior to my appt Mon?