Just caved into a carb brekkie, porridge with apple and blueberries( Why!!!! Oh well, I am back on it now, low carb for the rest of the day and lots of water, damage limitation.
You're doing 40g carbs a day aren't you? Keep the rest if your day virtually carb free and you may just get away with it. If not, it will help you on the way back to ketosis xx
Just put it behind you and eat as low carb as you can for the rest of the day. I had plenty of days like this last time i did atkins and it didnt really affect things so try not to be too harsh on yourself. xx