My wonderful hunk of a husband turns 40 today, and his party is tomorrow. There will be cake! Of course!

I'm only in my 2nd week of PB, have had many major improvements in digestion, sleep, energy levels, etc. I've also lost 4 lbs. If I have some cake and party foods tomorrow, will it make me feel like total crap? Could I possibly count it as a "re-feed", since I haven't done that at all since I started? Will it affect my weight loss negatively?

I understand you guys can't tell me for sure what my body will do, but your opinions are appreciated. I made the cake, I want to be able to eat some too, but I won't if it's really not a good idea.