No, not wrong at all. But you don't need to be in ketosis to lose weight, you could be eating 400kcals a day of pure carbs and you would still lose as much weight, but you would most likely not be in ketosis, because you would be topping up your carb stores. Which would mean the headache, carb cravings, hunger pangs etc would be hell! The process of ketosis is basically forcing our bodies to enter starvation (in a controlled manner). We depleat our glycogen (carbs) stores to the point where our bodies have no choice but to start breaking down our fat stores to produce energy. Our bodies will always use carbs before fat as it's easier to break down and readily available....therefore if you go off plan and eat some carbs, you body will switch to using them up before returning to fat stores and ketosis. If you didn't eat many carbs, then it wont take very long at all for those reserves to be used up and the body to return to ketosis.
When you eat carbs, they are first stored as glycogen, then when your glycogen stores are full they are converted to fat for later on. Where as protein cant be stored as fat, if you dont use it you lose it...which is why if you've got to eat then stick to protein! There is no risk of it being converted to fat.
The problem with relying on ketostix to tell whether you are in ketosis or not, is that the ketostix doesn't actually tell you if you are in ketosis or not?! It only tells you if there are ketones present in your urine. Ketones are the by product of the ketosis product. So if the ketostix shows up positive, it merely means you have been in ketosis at some point in the recent past, not necessarily at that moment in time. The same can be said, if you get a negative reading, you may be back in ketosis, just not passed ketones through to your urine yet? That's why a lot of people say not to rely on ketotix...or not to be down hearted if they dont give you the resding you are expecting? Saying that, I use them all the time