Ugh! Should I take a break?

I am so frustrated.  I lost 18 pounds since Feb (I know, that's really good and I'm happy), but the last month has been HELL regarding the scale and the measuring tape. I'm 5'8" 160lbs 27yo Small Frame Female. Here's what's been happening:

The entire month of April I weighed 160lbs, despite have a deficit and working out 5 days a week.  I figured the lack of weight loss was due to my period...fortunately it was! I lost 3pounds after four weeks of nothing. Yeah, right?  Nope!  The next week I weighed myself and those 3lbs came back.  "okay" I thought "it's just water weight or something...no big deal", although it was discouraging. Nonetheless, I stepped up my game, was stricter with deficits and continued to workout (eating zig zag prior and cutting back to around 1600 M-F). 

A week later (today) I weighed myself and barely lost 2 pounds.  I know this is normal, but after dropping 3 from my period, gaining them all back and then only going down 2 makes no sense. 

I'm weighing/measuring all my food. I dine out once every 2 weeks or so (and never go overboard), drink plenty of water, high fiber/protein and try to monitar my sodium the best I can.

Now that you have the background, here's my question:
My sedentary burn is roughly 1800.  SInce I am at a "healthy weight", I am thinking of maintaining for the next 2 weeks and eating at that number. I still plan on working out because I'm teaching myself to run for my first 5K in June, but the deficits will only be b/w 300-600 (I think) on workout days.  What do you think?  I've ordered a Polar F7, but it's on back-order and I can't wait until it gets here to help monitar cals and HR.  I feel so jipt.  I workout hard and eat right, with a small dessert (100-200 cals and nothing overly-processed) almost every night.  I'm bummed out.

*bump*

I know what you are going through. The thing is, your body adjusts to the diet you put it on. Crappy, right? It gets used to the deficit and makes up for it so you WON'T see any weight loss and small digressions could lead to that mysterious gained pound. Here's the thing to do: mix it up. some days eat to your body's FULL needs, (2,000 calories here!) and some eat your normal deficit. What I do is eat to a deficit 6 days of the week, but on Shabbat (hooray, judaism!) I sit down to a full meal, chose the healthier options (it's community potluck style most nights, or at a different family's house who will cook for 20-30 people) and quit caring for that one night. wine? yup. noodles? yes, please. lots of salad, obviously, but also some dessert and the thick white homemade challah bread...mmm. and i don't step on the scale saturday, because i know i'm going to be retaining that weight. But come Monday, I'm usually down at least half a pound. (and that is where it counts!)

Is it possible that you've miscalculated the # of calories you're burning? For instance, maybe your body was burning more calories back in February, but now you weigh less and you're moving around 18 pounds less during every exercise. That's the best I can come up with... good luck!

I'm having the same problem.  I started changing my eating and exercise habits in late March, joined CC in April.  I have lost about 8-10 pounds since late March but the entire month of May, I've been the exact same weight.

I'm 30 years old, 5'1", large frame, 160 pounds right now and I've been eating between 1200 and 1400 calories a day.  I do weigh and measure everything*.  I drink nothing but water.   Vegetarian.  The exercise I do is 40 minutes on a stationary bike (I go a little less than 7 miles distance in 40 minutes so it's not too strenuous) OR I play Dance Dance Revolution (burning between 200 and 500 calories according to the calorie count in the game and who knows how accurate that is).  No matter what activity level I set myself at, CC tells me to eat 1200 calories.  I don't know if this matters but I have a high resting heart rate... around 100bpm doing nothing and it's been like that for as long as I can remember.

* I bought the scale at the beginning of May which is funny because I stopped losing weight after I got it and made sure my portions were correct.

I took the day off yesterday.  My fiance took me out to eat and I ate without counting.  I don't know if that's good or bad.