That is a lot of weight in a short period of time. It's important to keep weight loss in perspective and realistic. The first week is mostly water and then weight loss usually levels off. You may not see a change on the scale for a week and then it will drop. Many things factor in to weight loss including our genetics, age, current weight, diet, exercise, types food we eat, activity levels, sodium intake, ect. The important thing is to stay consistent and keep going. It all evens out. Good luck!