Don't worry Izzy, provided you are drinking plenty of water there is not a problem.

What your Matron was probably talking about was ketoacidosis where you excrete a lot of ketones and that is because your body is eating up itself. The cause is very different and can have very negative health effects. Many people seem to get the two confused.

Just make sure you drink plenty of water to keep those ketones flushed out of you. You do not need dark purple strips, just a faint pink, to know you are in fat burning mode.

Keep at it and don't get discouraged.