So, we went off to Urgent Care this afternoon, spent most of two hours waiting, then they passed the buck back to Dr. Ciccinelli. It appears I have indeed picked up a minor pin tract infection, which isn't uncommon.
Upshot of the whole thing, so far: the last external pin is out three days early,and I have a prescription for antibiotics which we couldn't get filled because, at 6pm on a Sunday, the pharmacy was (not unexpectedly) closed. We'll get it filled tomorrow morning. I'm supposed to go back and see Dr. Ciccinelli anyway on Wednesday, when the pin was supposed to come out, and in the meantime I'm under orders to stay off it, keep it elevated, and keep it dry.
Have I mentioned lately how much I hate crutches?