I think you'll be fine if you draw a very thick black line under the blip.
Having said that, while I agree with what Lealou said - that you're going to be down 9,000+ calories this week (I make it more, actually) the problem with this plan isn't calories. It's the fact that water and glycogen regain can have a massive impact on your weekly loss, which in turn can make you feel despondent and like you want to give up.
That massive amount most of us lose in week 1 is approximately 50-75% water and glycogen. Glycogen is what the body stores in the liver and muscles after consuming carbs and most of us can store up to 2,000 calories worth of the stuff, about a pound in weight. Unfortunately, glycogen is bound to 3-4 times as much water, which means that when you lose that pound of glycogen, you lose another 4lbs of water with it. So if you eat a significant amount of carbs again, you'll put five pounds back on in the blink of an eye. Hope that makes sense.
So, if you have a blip, you can put a good couple to five pounds back on overnight (and sadly, they don't always come back off again overnight - it can take a few days). This means that when you weigh in on your usual weigh day that it might appear you haven't lost as much as you should've done - and then you get the miserable feeling that you're trying really hard for nothing, that you're wasting your money on packs, etc. In the longer term, a few hundred extra blip calories make no difference at all, but in the short term, seeing those additional pounds can make many of us lose the will to keep going.
Try not to blip. Just tell yourself that eating normal food isn't something you do at the moment.
Hope today's been better x x
