Confused on total calories??

Options
I am totally confused?!?!?! So I have my UP armband synced to MyFitnessPal. Ok we'll I was at a -1 for my calories at 7pm tonight (I go midnight-midnight). I made sure to get in a 1 mile (plus some) run/jog/walk in. Well as I was submitting my food diary for the day, it now shows me -40 cal?!?!? I don't get it. I didn't eat plus I exercised. Any clues??