It's always possible that some of the fluids given in the hospital are still in your body but settled in your legs. Mine settles in my abdomen.
Yesterday my Surg told me that each bag of fluids is 2.5 lbs.
I also had low potasium after the surg; Surg suggesting adding a little bit of real orange juice to my water in addition to bananas - mashed as I was in the pureed phase.
Was initally concerned about the OJ since I had GERD & heartburn so bad before the surg but haven't since it's returned.
Elevate your legs when possible & move around & walk as much as you can to get the circulation moving.
When in doubt, call back again. Your team should be concerned that your concerned.
My surg told me at my 1st appt yesterday that patients often have once side effect that requires discussion, etc.
Best wishes in getting your legs back to normal. I had more problems w/the fluid in my legs earlier but it's started go away & hopefully in time I may lose my cankles.