Ugh, it is SOO infuriating, isn't it?
My body is known for doing this! If I have a splurge day, if I am ovulating, if it's TOM, I will jump 5 pounds like it's nothing.
Because I know this it is precisely why I do not weigh daily, only weekly, and once my loss slows down when I get into onderland I may only check bi-weekly.
My suggestion is to keep at it and check back in a week. Give your body time to adjust back.
Key is not to be too hard on yourself and just keep at it. Stuff like this is what would derail me in the past... when I would jump up like that I would say all this work isn't worth it and off to eat I went.
Hang in there!! Don't let the curse of the scale get to you.
I totally feel your pain!