That really sucks. Have you called your doctor to make sure everything is ok and normal? You don't want to wait again just in case.

It hurts because it is healing. You have experienced a significant injury and invasive surgery. As a shock mechanism, your nerves shut down when traumatized. Well, they're waking up again. It means you are getting better. Your pinky will regain motion but you MUST do all your physiotherapy religiously. So no more underground bare-knuckle fights in Yau Ma Tei, OKAY?!?!?!

wow, you're making me worry. please grin and bear it and talk to the doctor if it persists!