Use The Mirror, Not The Scale
It wasn't that long ago that I used the scale on my bathroom floor as a barometer for how my diet and exercise plans were doing. I ran at least 5 miles every other day....and not just flat road runs, I was running hills that served as ski hills during our winter months (still love trail running, btw). I weighed myself every single morning before I hopped in the shower, usually around 6:45am. My weight was 199 +/- 3lbs. On the days that I didn't run, I'd drink some beer, have some cheese, but overall I stuck to my relatively low-carb diet plan. Through all that running and eating 'right', I still had that bit of fat around the waist that I couldn't get rid of. I continued running and eating what I thought was a good diet. Fast forward through to November 2012.....
November 2012 was the month that I broke some of my rules. I went on three hunting trips, one out of state and two in state. While I was on those trips convenience food was necessary. I wasn't eating garbage or junk foods, but I was eating pizza, bagels, sandwiches, toast, etc, simple foods that were easy and filling. I weighed myself before leaving for my last hunting trip.....212lbs. I felt fat.
When the calendar hit December 1st 2012 I committed to two things, changing to a primal diet and doing three months of P90X Lean. The extra 10 lbs that I 'found' in November fell off right away, thankfully. And, another quick change was the view in the mirror. I weighed the same, but the clothes were fitting differently. I used to be able to wear the clothes from my 'fat' days (pre June 2010), but those were no longer just too big for me, they fell right off of me.
Long story short, use the mirror and your clothes as a barometer, not the scale. I still weigh myself every morning out of habit and curiosity (196.5 this morning if anyone's interested). But, the change that I see in the mirror is where it's most noticeable. Body fat continues to disappear and muscle is getting bigger and showing itself. Your scale might not change, Hell, it might even go up if you're building a lot of muscle. Don't worry about it. Use the mirror. I did, and I'm going to keep using it.