Diario de LJay, 13 sep. 14

Keep an eye on your sodium intake, it could be water. And with that much walking you are probably building muscle, which is a good thing. 

Well if your doing WW, try simple start. Lot's of people had great success with it. We all have gains along the way (even when we do everything right). Google "why the scale lies" for insight in to water weight fluctuations. If you haven't read it yet. If you are doing WW, make sure you are getting in your HG's, your oil, your water. Watch those bites, licks and tastes (my downfall). I also keep track of my caloric intake while I do WW. It lets you know how much you are eating. If you are doing a different diet, then make sure you are eating the correct amount of calories to help you lose. The scale might be a fluke this week. Maybe you just had too much sodium yesterday. It could be a lot of things. 

Try a complete fast (Only water) 1 day a week until your body realizes you want it to burn your fat stores