If you can manage it, it kept me sane to weigh in only once per week at the same time, wearing the same thing (nothing!). I think many fluctuations occur over the week and you'll probably get a more comprehensive (and accurate) idea of progress by looking at a consistent interval as your number and the daily or in-between weigh-ins are unofficial. My weight fluctuates all week, especially if I'm sore from a work-out. Your muscles can store a lot of water when they're swollen. Anyway, food for thought :)