If you’re eating very low carb, then it’s likely you’ve entered nutritional ketosis - a state where your body is burning fat for fuel, in preference to carbs. This is perfectly safe for someone not on any medication.
Nutritional ketosis is very different from a medical emergency called DKA or Diabetic Ketoacidiosis which occurs when the body runs out of insulin and produces ketones. This will usually occur in tandem with very high blood sugars and is most common in those using insulin.