So the important thing to realize about the serum calcium level is there are a couple of ways to measure it. One, called 'serum ionized calcium', is very accurate. The common calcium level checked on a standard screen is not very accurate because it has to be corrected based on serum protein.
But let's say that your level is really eleven.
HERE IS A GOOD REFERENCE FOR YOU ON ELEVATED CALCIUM LEVELS.
People with elevated calcium levels need to have their PARATHYROID gland checked, not their thyroid, so you may have miss heard this part.
If you have recurrent kidney stones I am glad you are with a Urologist. If you have had an isolated stone I doubt this calcium level is truly elevated. Still, now that the result is 'high' it is important to check.
I think the doctor will check your parathyroid function and find it normal. I understand your concern, but from a doctor's perspective an isolated calcium reading of 11 is not worrisome, especially if the test was a standard calcium test and if the reason for the test was that you had a kidney stone.
Please let me know if you have any questions about my answer.
Positive feedback always appreciated.