Staying at a deficit??

calorie deficit is simply the amount of cals you need to lose weight (under your maintance cals), e.g.

I maintain my current weight at 1600 calories a day, in order to lose weight, i need to eat less than that a day.

If i want to lose weight fast, i'll eat wayyyyyy under that, if it want to lose it at a safer more recommended slower pace, i'll eat about 200-300 cals less that that.

Last summer i lost 1lb per week by keeping my cals at 1200 a day
Right now i want to lose much faster so i'm eating 1200 cals and exercising 400 cals, which in total is a whopping 800 calorie a day deficit, but this means i lose 2lbs a week.

if you've entered your information and weight loss goals accurately and realistically into MFP, then the daily calorie goal you're given has you at a calorie deficit. You can eat TO GOAL every day and you'll lose weight, because that number is fewer calories than what your body burns in a 24 hour period - sleeping, walking, working, folding laundry, grocery shopping, etc.

If you exercise, those burned cals are added back into your daily goal because burning off more creates a much larger deficit - which might sound like a good thing, but it's not, especially over time, because you're not giving your body enough fuel, which can lead to a whole host of problems in the long run. So your NET cals should be at, or at least very near your goal at the end of the day.

MFP is a great system and works well when used correctly. The closer you get to your weight loss goal (and by your ticker it looks like you are really close), your deficit should be smaller, and the weight loss will be slower, but keep at it. Make sure you take measurements as well - often you'll see inches coming off while the scale doesn't move much.

Edited to add: to make sure you're at a reasonable deficit, check your loss goal settings - set it to 1/2 lb a week.

when you put in that you want to lose X Lbs per week and MFP gives you a calorie goal...that goal is a deficit of calories from your estimated maintenance calories...that's why you put all of the information in. With little weight to lose just plug in that you want to lose about 1/2 Lb per week and hit that calorie goal...it's easy...the calculator does all the work for you...that's what it's here for.