Yes Karen, I went through the same thing. At about three weeks out I began exercising and I stopped loosing weight. It took about two and a half weeks to start loosing again.
As the others told me, your body needs to catch up, so it stops doing anything for a little bit. Once you catch up, you will watch the weight fall off. I was so bummed I would cry while I exercised! This too shall pass. Just don't stop exercising. I didn't and now it is working for me. Tomorrow is another day!