Yes, as well as bad breath amongst other symptoms. (Lightheadedness, boost of energy, lack of appetite etc. Everyone don't experience all of those, though.)

I don't bother with Ketostix, as they can be utterly misleading (dark purple could be dehydration, no colour could mean you're already burning your ketones so there are none left in your urine while you'd still be in ketosis, i.e. good etc.)