Please help with no weight loss

Hi everyone! I have some questions. I started my pre op diet on Nov 13, surgery was Nov.  20. All together I have lost 33 pounds. Three weeks ago I gained 3 pounds. I finally lost those extra pounds. But for the last 2 weeks I  have stayed the same. Am I over eating or doing something wrong?  I try hard to ge****er in but I know I do not get all I need in. Same with protein and I started walking on a treadmill last weekend. I tracked my calories and I think for the most part I'm staying under 800 calories a day. I am 5'3 and 188 pounds. Thank you all for the advise, I just don't know what I need to do. 

It could be your caloric intake.  I try not to go over 600 calories per day.  Make sure to consume the recommended protein as well.  Another tip is to keep a food journal.  This helps me  tremendously! Log every bite that you eat.