You say "besides the weekend" but perhaps you cheated enough for the whole week this weekend? I am not saying this to be mean but I know that I have done that myself. It happens to the best of us.I have let myself go on the weekend and slowed down my progress for the week. It could very well just be water weight from your period. I wouldn't worry about it too much. Just stick with it and remember that you are doing this for long term weight loss , not a quick fix, good luck!