it's best to check with your Endocrinologist about calcium levels, but usually shouldn't take long to have your calcium back to normal. When I had my thyroid taken out, they would do test on my face to check for low calcium. If you gently hit your cheeck/jaw area, and it twitches, or if you feel tinggly around that area, it means you are low in calcium. But it's Best to ask your doctor, he might do blood work on you.