Running backwards

At least that's how I feel these past couple of weeks. I managed to lose around 3 lbs and 2.5 inches over a month, but in the past two weeks I've gained the weight back, and half an inch to boot. I'm working out hard five days a week, and trying to stay at least a little bit active on the weekends. I've been watching my caloric intake, and don't think I've been that out of whack. Of course, every calculator I use tells me I should be eating a different amount! Spark says around 2000, another says around 1600... my PT says 1750. I don't know where to start! Just frustrated to be slipping backwards after working so hard to gain what little ground I have.