Tracy,

Karen mentioned hormones.  Could that be it?  I used to have increase my basal and bolus insulins about 1 week out of the month of my cycle.  Hormones can do horrible things to your blood sugars.  Of course there are so many variables that can be causing these problems that it's tough to say.  Everyone else has mentioned a lot of the factors that could be causing your problem.  You have to be a detective and look at one thing at a time to see what the culprit is.  It's usually worth it in the end though. 

Terri