Hi hun - for my 2 pence worth.... I blame the exercise. I know it's mad to say that, however, in May I cycled 70 plus miles in about 3 weeks, yet lost tiny amounts, even though I was sticking to plan.
As soon as I stopped exercising so much (becuase of surgery) I had massive losses.
I'm not saying to give up exercise though as it's a great mood booster etc and makes us super healthy, but give it a few more weeks and your body will give you the results you deserve! x