Hehe, I guess everyone is right on this one.
What I'd say is that you and only you know your feelings the best.
I weigh in once a day (the morning after toilet time, and naked). I do that since November 3rd. Since I'm a guy, I don't have those problems with that "time of the month". However, it happened 4 times that I gained weight and countless times that I have stalled... Never cheated, never did anything wrong by the program.
HOWEVER, I personally think weighing at the start of the day is a great way to.... forget my weight! In fact, if I progressed, I am more than happy. If I didn't, then the "did I lose or gain weight" question gets out of my mind, since I satisfied my curiousity. And on those days I gain weight, well I just tell myself I never did anything wrong with the program and it must be water retention or scale problem (never know!).
Go with what you feel is the best for you. You wanna weigh yourself? Do it. Some morning you don't want? Then don't.
Just think of the scale as a tool to help you. Be wise with yourself, if you cheated and you know you gained weight, double your efforts and weigh only in 3-4 days.
The scale must NOT be an obstacle, it's a tool; think of it as motivation. If it's not for you, then throw it away for a while