Wow,, that's amazing, I got the same result when I first ever started CD I lost 12lbs in the first week, your second week may not be so dramatic as your actually loosing fat rather than water. It averages out between 4 and 7 pounds, but don't be disheartened.
I've recently restarted yesterday so hopefully I get the same results too, but I know the buzz you felt when you was told about how much you lost.
Wishing you all the best