I started a lowcarb diet 2 wks ago. All went really well. I lost 10 lbs per wk. This week though not 1 lb. Does anyone know why?

There is no way you can sustain 10 pounds per week losses. When you start any restricted eating program, it is common to lose more than normal the first week because of losing water weight. That effect is exacerbated on low-carb plans. Remember that the scale does not show you all the changes going on in your body. Losing 1 pound per week is NORMAL and desirable. Just realize that 8 or 9 pounds of the weight you lost the previous weeks were water, not fat. Now that you've gotten rid of that excess water, you are only seeing the fat losses.

Thanks for the info.