not to burst your bubble Lodid, but when you come off the KEto diet, be prepare to regain around 5-10 lbs of waterweight if you just introduce carbs back into your diet right away... my advice is to slowly go up in carbs around 10g a day or so, or around 25-50 a week, not going to fast, but whatever is comfortable to try to avoid the water regain.
As for losing 11 lbs in 3-4 days, when I restart a CKD, I now do TKD's to help with workouts, I could lose around 10lbs in a week of water, depending on how my diet was at the moment, but normally I count on losing around 5-7lbs in the first week or so, so I am not sure how you would lose 11, unless it was after a carb up.