You can still do a bit of damage limitation. You could go low carb for some of those dinners. Or you could say 'sod it , its my birthday' and have whatever you like. I could never do the 'sod it' bit because i would be so depressed about gaining, but as long as you have a plan in place for your recovery you have done the best you can. I really hope you have a fantastic time whatever you decide to do. You will look amazing no matter what weight you are , remember nothing tastes as good as being slim feels xx