What in your life, in the gym and outside of it, changed around that same time? New job responsibilities (your profile says "fitness instructor, is that like a trainer or do you lead group cardio classes?); any change in diet; tweak your training program at all; lose any bodyweight? Basically there are a ton of variables still left unaccounted for.
Without knowing more details, you could try eating exactly the same and drop the lifting for a while like Yogi said, or keep the training pretty much the same (maybe reduce the intensity for a bit) while bumping up the daily calories.