Well, six days since my last workout and I was getting worried that it wasn't healing as fast as I'd like. It was still painful to do crazy things like throw a ball or blow my nose.
I thought of contacting the local GP but, in the expectation that he'd do little more than prescribe rest and Ibuprofen, I called the chiropractor instead.
He prodded around and assured me that I hadn't popped a rib. His opinion was that I had an acute muscle spasm. He said it was impossible to rule out a small trauma but the complete absense of bruising and pain from pressure indicates nothing more than spasm, probably due to overuse. He also found a couple of major muscle-ridges to which he applied some ultrasound, massage and ice-hot then sent me packing after a bit of mandatory back-cracking.
I think I might go in and do some, maybe, 50% weights tomorrow. I asked him whether I could consider getting back into the program and received the expected answer.