I have had a horrible week....I have been so stressed and fell off plan, eating all carbs and no veggies...not drinking enough water, etc. To my surprise...I have lost almost 5 lbs this week?!? Does stress burn more calories?
Stress burns calories if you exercise to help ease it. Stress itself doesn't do anything Perhaps your body needed a shake-up, a change in your eating routine? Sometimes eating more than normal for a short time helps your body lose a couple pounds. That's the idea behind calorie cycling (or the wendie plan for WW).
Make sure you get back OP. You could also be a bit dehydrated. Don't be surprised if you get back OP and go up. That's happened to me, but your body gets readjusted and the weight will come off.