Question!! please read.

If I eat too much one day, like say 1400 calories, and then i eat like 1000 the next day to compensate for it...is that fine? Even though you're supposedly supposed to never go below 1200, if I have extra food in my stomach from the day before would that be fine?

No. It's a new day. Your body still needs atleast 1200 just to operate it's organs. It's not like your heart is going to beat any less.

 

1400 is NOT over eating. You STILL have a deficit and will lose weight. It takes 3500 calories over your maitanence (which should be around 1700-2000+ for a woman I think) to gain one pound.

No, don't eat below your RMR, ~1500 for most teen girls, but since you're 4'11" you are shorter than the standard so a lower number of calories is correct.  Your RMR calculates out to 1,117. Given your stats, if you're completely sedentary, 1400+ calories is what your maintenance amount is.

Wait, if my rmr is 1,117, then why should i eat 1400+??

RMR is not the same as maintenance.  RMR is if you're in bed all day long doing nothing (not sick as being sick actually does burn calories for recovery).  Maintenance would be if you actually walk around like a normal person, standing, sitting, going and doing things.  The more you exercise, the more you would need in the way of calories.

oh ok, thank you