A couple of things are going on here.
First, by your username, you appear to be a woman, and therefore your hormonal cycle is going to affect your fat loss.
Second, remember that you want to lose fat, not weight per se, because one of the things a well-formulated ketogenic diet can do for you is to increase your muscle mass and your bone density. This means that you can lose fat without necessarily losing weight. It is why we often say that keto is not a weight-loss diet, but a weight-normalization diet.
Third, a well formulated ketogenic diet has numerous health benefits, including reversing insulin resistance, lowering inflammation, increasing mental clarity, and improving cardiovascular health—all because of the lowered serum insulin level such a diet permits.
Fourth, the real goal is not so much to be producing ketone bodies as it is to become fat-adapted, a state in which muscles are using fatty acids for metabolic fuel in preference to glucose and even in preference to ketone bodies. This allows your body to make use of its store of excess fat, part of the weight-normalization I mentioned above. Fat-adaptation can take up to eight-weeks, sometimes even longer, so what happens in your first week is essentially irrelevant.
Lastly, if you are approaching your ketogenic diet as you would if it were a normal weight-loss diet, you are probably restricting your caloric intake. For various reasons, this is a mistake. Eat enough food to satisfy your hunger. At the beginning, this will be a scarily large amount of food, but as your serum insulin drops, your brain will start registering your satiety signals again, and it will set your appetite at a more reasonable level. You will most likely be eating at a caloric deficit, but the point is that you won’t be imposing such a deficit on your body, your body will be signaling to you, through your appetite, that you have given it enough. Only then will it feel safe parting with your excess fat.
