hurt knee

today in JROTC we had to run the mile. i was feeling great until the 800 meter mark. right after half way my knee started buckling and it hurt to run. i pushed through it and got a 6:35 mile. i know i couldve done way better. my knee still hurts when i walk. i talked to my cross country coach at practice and she said that i probably just tweeked a tendent. i hope thats it. i meet with the Air Force recruiter tomorrow at 3 oclock