If the scale goes up, that's perfectly normal. Your weight is not a static number. It really does go up and down for many different reasons that have nothing to do with the food you eat. Ever notice your weight goes up during TOM ? Most women tend to gain weight during their menstrual cycle. Is that a fat gain ? Nope, it's nothing more than a temporary water weight gain that passes in a few days.
I can easily "gain" 3-4 pounds in a day ! Is that a fat gain ? Not unless I ate an extra 14,000 calories ON TOP of my normal intake. one pound of fat = 3,500 calories. So, if you know you haven't been eating a piece of cheesecake every day, then you know you didn't gain weight.
AND even if you did eat a little too much on Thanksgiving (we all did quite frankly), it doesn't mean you did something wrong. You can't and shouldn't tie your emotions to the scale. Yes, it's important to maintain a healthy weight, but there is more to good health than a number that stares at us from between our toes in the morning.
If you're truly worried about what the scale will say... then skip this week's weigh in and wait til next week when you're calmer.