Jayne's right, I have the ketostix as well and as long as they change colour, no matter how slightly, then its a positive for ketosis. Remember that only *excess* ketones are detected so if you don't have any excess to be secreted you can get a negative result when you are in fact still in ketosis. Make sure you test first thing in the morning as it gets diluted and I know personally only my first test is ever positive, all the rest during the day are negative due to all the water we drink hehe