I know it's too early to be frustrated but....

Here I am two and half weeks post-op and things were moving right along on the scale.  I hit -10 lbs. and then jumped up 3 on the day I started my period.  That's where I have stayed.  Now, normally I would NOT complain about losing 7 lbs. in 2 1/2 weeks BUT everyone says they lost the most the first month after surgery.  I keep looking at my food journal....I am only eating around 800 calories.....how can I NOT be losing any pounds????  I thought maybe I wasn't eating enough so today I am trying for 1000 or 1200 calories to see if that helps.  (Prior to surgery, I was trying to eat between 1200-1400 cal per day and was able to lose 25 lbs. over six months.  Now I am having less and nada........)

Can anyone explain this????