Over the past few days I've noticed some pain near my left knee, on the inner side of my leg. It's fairly mild, and there's no swelling. I suspect it's either an MCL sprain or PAT (Pes Anserinus Tendinitis). At this point I don't think it really matters which it is, because the treatment for both is to get some rest (and ice, compress, etc.).
With my first HM only a couple of weeks away, I feel like the best thing for me to do is to get to the starting line without injury. Missing a few runs this week might affect my performance a little bit, but I don't feel like it will make a huge difference at this point. I feel confident that I can at least cover the distance, and my primary goal for this first HM is just to finish. I can't do that if I try to push through and turn this minor condition into a more serious injury by continuing to run on it...
...at least that's what I'm going to keep telling myself, because it's hard to take a break from running, especially with a race coming up.