What gives?

Sigh. I took my measurements again today. The only change was in my tummy, which went up .5 inches. Six weeks of Biggest Loser and essentially no progress on measurements. I'm seeing it on the scale--I didn't have a good weigh-in last Friday: I went up a pound and a half. Two weigh-ins since I've lost anything...but I was still down 5 pounds, so why no change in measurements?? On top of that, I weighed myself Monday (a no-no, but I had a bad weekend and I was checking the damage) and I was down 2.5 pounds since Friday. So, it canceled out the 1.5 increase from Friday and down another pound from even my lowest weight thus far. Technically unofficial, and I didn't record it on MyFitnessPal for that reason, but it happened nonetheless. What gives?