Hey there.
~Side note: Well first off you're only in an inch taller than me and we are the same weight (my ticker is off), how the **** do you fit into an 8, even snugly? I'd die to squeeze into a 10, I'm jealous!!!
On topic: Do you know how many calories you eat? When you say you haven't lost weight, how long are we talking here?
I looked at your exercise log on the exercise challenge; cardio looks good, but how long are your walks/runs taking? Have you tried adding strength training in 2 or 3 times a week? I know several months ago (before I fell off the wagon) when I hit a major plateau I was just doing cardio and abs and when I added strength training in it totally started me losing weight again!
Anyway, I don't have any theories yet so hopefully when you answer the questions it may be more clear!
***EDIT*** It looks like you just started losing weight August 28th! I think you may just be being a little impatient if nothing else. I know it can be frustrating but sometimes our bodies just don't lose it as fast as we want it to.