Welcome to the forum...This is a great place for information!
As I see you're getting lots of!

There is an entire chapter on slow losses in the Atkins book you may want to re-read as there are lots of different things that can contribute to a slow start.

If you have repeatedly dieted previously..especially low fat, medications, hidden carbs eg; "LC" bars, just to name a few.

I second all the other good things Wbahn and Dani have told you...do start a journal and record all of your food & drink as we have no way of knowing if you are drinking 1 liter of water or a six pack of diet coke and 3 slices of pizza!

Looking forward to hearing good things!

Bsayne