Thanks, ladies! It ended up being a HUGE ordeal!

I got there at 8:30 for my 9am appointment (had to drop off the hubs so I ran early). I got seen early, talked to a physician's assistant, got sent for x-rays to make sure there was no stress fracture... then 20 minutes later, the PA said "oops, the surgeon is taking over." Another half an hour, and I go for more x-rays... and at 10:30, I finally see my surgeon. Turns out, he was quite concerned that my 2009 surgery had failed. I know he thinks I'm stoic with pain, but, uh, if my tibia had fallen apart, I think I'd be more than a little hysterical.
It turns out I have tendinitis. Rest, ice, stretch, strengthen, and don't it if it hurts. Pretty much as I thought was likely, so I can't believe how much time I wasted! I even told EVERYONE (nurse on the phone, surgeon via email/on the phone, the PA) that it was probably from overuse.
Oh well. Guess it doesn't hurt if I don't walk. Looks like someone's not going to meetings for a few weeks more, eh?