A lot of the first pounds lost is water but there is fat in the total too. So Iowa girl is right: the next week will probably show little or no loss. But that's normal and not at all bad.

You have had a wonderful beginning. Now prepare to patiently and persistently follow the plan you have chosen. Try to avoid the high carb stuff (carbage) for as long as possible, because you will never again lose as easily as on this 'first try'.