With trauma to the muscles and nerves that affect their function, I would expect gradual improvement over the next three or four months, maybe more. As you start to see improvement over the next month or so, you can expect progressive improvement in subsequent months.
3 weeks is way too soon to be worried. so don't worry! Think positive and be patient and eat well and rest. You will heal. Ir great your seeing some slight movememt it means it is coming back! It takes time. Take good care of yourself now. More problems occur from the patient not following after care instructions. Seriously :half the job is on you so relax. Now is not the tine to stress out! Give it at least 8 weeks! That's still early.
Good luck -Seroma