From what you've described, I don't think your lower leg pain is anything serious. However, I'm going to ask you some questions and it would be very helpful if you would answer each one individually - numbered as I have done - in as much detail as you can then I'll come back as see where you are ....
1. what are your pain levels right now?
(remember the 1-10 scale: 1 = no pain and 10 = the worst you can imagine. And don't compare this with the bone-on-bone pain you had before surgery!
) Also don't forget to include other forms of pain such as soreness, burning, stabbing, throbbing, aching, swelling and stiffness
2. what pain medications have you been prescribed, how much are you taking (in mg please) and how often?
3. how often are you icing your knee and for how long?
4. are you elevating your leg, how often and for how long?
5. What is your ROM - that's flexion (bend) and extension (straightness)
6. what is your activity level? What do you do in the way of housework, cooking, cleaning, shopping, etc., and
7. what kind of PT exercises and exercises at home are you doing? How much and how often?
Can you detail it like this
At physio or PT
First description - 5 reps x 2 sets
Second description - 10 reps x 2 sets
At home
First description - 5 reps x 2 sets 3 session a day
Second description - 10 reps x 2 sets 3 sessions a day