DVT or normal
Not sure exactly what the question is, but if you had an operation 3 weeks ago, and you have swelling in your ankles and feet, it is probably a normal part of the recovery.
If it is only on one side, or persistent, i would get an ultrasound of the legs to make sure you don't have a deep vein thrombosis
or dvt. While uncommon, they can be fatal if not detected and treated.