Are you really eating the # of calories MFP sets?

did you set your goal for 2 lbs per week? thats really the only thing i could imagine
If you have 75+ lbs to lose 2 lbs/week is ideal,
If you have 40-75 lbs to lose 1.5 lbs/week is ideal,
If you have 25-40 lbs to lose 1 lbs/week is ideal,
If you have 15 -25 lbs to lose 0.5 to 1.0 lbs/week is ideal, and
If you have less than 15 lbs to lose 0.5 lbs/week is ideal

i eat what mfp says, but i set my goal to 2lbs a week for now. if i set it to 1 lb i would be at my bmr. the bigger deficit you create, the more you chance going below your bmr.
did you include your exercise in your daily activity level? if not, you should log your exercise and eat those calories as well. MFP sets your dailt goal based on no exercise - so when you do some you should eat more.. on my heavy cardio days i eat 2200+ but my net is still 1520.

I eat between 1200-1300 a day most days, but I have a lot more weight to lose than you. You have to eat to keep yourself fueled, and you will find that once you input a hard workout it will allow you extra calories for that day if you want/need them.

When I said I wanted to lose 2lbs a week, MFP gave me 1200 cals per day.
When I changed it to losing 1lb a week, it upped to 1530. It's a big difference. You don't have much to loose so if I were you I'd change the settings until you get a higher calorie amount. Also, eat back you exercise cals

As a very active (5x per week weights, 5x per week running or elliptical and I waitress) 5'4" 29 YO women I just cannot see how I am suuposed to be eating only 1200 calories a day. I weigh 146 and am working on getting to 127. If you shouldn't eat less than your BMR that would give me a base minimum of 1460 a day right? How many should we really be eating?? Please help! Thanks so much!

Overtraining FTW

Why on earth are you doing weights and cardio 5 times a week?

Sometimes less is more....get a decent workout plan and stick with it. As for nutrition you might want to increase it slightly and keep an eye on your wieghtloss, if you haven't lost anything in 3 weeks make minor adjustments and repeat.

I end up eating less, I like to have a 100-200 cal buffer just in case, but a lot of times I have a hard time reaching my net goal.

You should watch your calorie deficit. It is recommended to have a calorie deficit between 500 and 1000 calories for weight loss. According to MFP your BMR is 1372. But then your also have your Active Metabolic Rate which is you BMR multiplied by your activity level. They are broken down into 4 groups
1. Sedentary- you sit in a desk all day if so then multiple your bmr by 1.1
2. Light - Are you on your feet more than half the day if so then multiple your bmr by 1.2
3. Moderate- Are you on the move all dayif so then multiple your bmr by 1.3
4. High- Are you always on the move and your job requires a lot of manual labor if so then multiple your bmr by 1.4

You sound like you are a 3 so your AMR=1.3*1372=1783.6 then add your exercise onto that so lets say you do 30 min on the elliptical and 30 min strength training burning 500 calories. Your total calories burned for the day would be 2283, so you would want to eat no less than 1283 but could eat up to 1783 and lose about a pound a week.

You can also modify your calorie goals on MFP under the MyHome tab section Goals, and once in change my goals select custom and you can change them to what ever you feel comfortable with.

I hope this helps I am a little bigger than you and a little less active and I keep my calories right averaged around 1200 on day I don't work out which works for me to 1450 on days I do. Plus I have a few naughty days every once in awhile, where I don't even think about the calories.

Source: Research I have done looking for the right calories settings for myself and the AMR calculations come from Jillian Michaels it has worked pretty well for me