On Monday, all my phone sounds shut off

I know it sounds crazy, but this has been happening for about 4 weeks. I wake up late Monday morning, because, while my alarm is technically going off, my phone makes no sound. There's no ringtone, no text alerts, no app alerts, no keyboard clicks and, most annoyingly, no alarm sound. There are no sounds throigh earphones or my bluetooth. Since it is early in the morning, I have not tried to make a call to see if that works. All I have to do is shut it off and turn it back on and the sounds come back. I've been having many sound issues since the begining of September, first with not getting a sound alert for Facebook alters(but I do get them if someone private messages me on Facebook) and after the iOS update, my email sound stopped, even though I have all the places where I can set sounds to On. All of my other apps work finr(except on Mondays). I have a 4S that is not quite a year old and have updated to iOS6. This Monday issue happened after the update. I hadn't made any changes to the sounds scheme before this happened. If anyone can help out, that woudl be much appreciated!

Erin