My family doctor's office called today. My bone scan is clear; there is no activity in my femur. Sigh.
As Ian pointed out, the bone scan shows bone growth and bone death, so it's possible that whatever is hurting is neither of those. It's also possible that whatever is there is too small for the scans to pick up, because they don't pick up anything that is less than about 0.5cm. It's also possible that the pain is somehow in the muscles. I don't think it's in the muscle, but I guess it could be - I feel like I have to poke past the muscle to make it hurt, and that it hurts more deeply than the muscle.
Of course it's also possible that the pain is all in my head, but I poked around the leg and made it hurt again so I'm pretty sure that the pain is there. :)
I'll see my family doctor next week to figure out what we can do about this. I hope that he requests a CT scan or an MRI - either of those should show what's going on, if there is anything that's there. Both of them certainly show more detail than a bone scan, which should be helpful.