There are a lot of variables. Calculators are a rough guess, not always accurate. Consider the following:
- are you sure that you're eating 2200-2400 calories per day?
This one can be easy to get wrong. Do you weigh and/or measure everything? Today I took a medium apple (which my calorie program says is 81 cals), but I weighed it. It was 101 calories instead. That doesn't sound like a lot, but if you're off on everything it could add to extra calories. Often packaged items will read 1/2 cup (30g) but when you weigh 1/2 cup it's way more than 30g.
- what type of exercise are you doing?
Any exercise that taxes your muscles (and if you've been inactive and are suddenly active, this could be any of them) causes you to retain water. I lift weights and almost always see a 1-2 pound gain the next day. It goes away on the 2nd day though, usually with more weight.
- are you consistent with your water/liquid intake?
It sounds odd, but if you don't drink enough water your body tends to hold on to what it has for dear life. So make sure you drink plenty, adding more on the days when you sweat it out.
- where in your menstrual cycle are you?
You can see weird swings around your period. I think others are different, but in my case (most months) I can pretty much pick the day it will start. A few days prior I'll gain 2 - 4 pounds, then drop them overnight.
- sodium intake?
I don't often see much difference, and I don't track it, but I know some people retain a lot of water after a particularly salty meal.
So, how long have you been tracking your food intake, and how much weight are we talking about? I'm not sure about medications that might affect your weight, but they might as well.
Oh, and