Yep I weigh every day and sometimes twice ! I figure I'm not hurting anyone and it doesn't do me any harm so why not. BUT if you feel that it hinders your weight loss then you should try and keep weigh in to your official day at class.
Yes I am a serial 'scale hopper' as well. As long as you are able to accept that your weight can vary during the week, and don't go of the rails when the scales are unkind to you. I don't see any harm in it.x