This morning, when I awoke at about five a.m., I got up to feed the cats, who were hounding me mercilessly. The pain in my left calf and knee was bad. I had to hold onto the wall and work my way down the hall, taking deep breaths, trying to stay upright. I went back to bed and slept for another two hours, and when I woke again the pain was much less. As I got dressed it was less and less and I was able to do my usual workout at the gym without incident, except for one time. I was doing "resisted hip" exercises - extension, abduction, adduction - with my left leg in a loop, my right holding the floor down, when suddenly my left calf went into another pain strike, similar to what was happening yesterday. Fortunately, it came out of it and I was able to finish my workout and get home without any further incidents.
For the rest of the day it has been its old self. I am even reminded of what it is like after I have a particularly bad headache: it seems better than before. I don't think it actually is better but I feel such relief that I almost float.