I have been eating zero carbs for two weeks now and the keto stixs will not change color!I do drink a lot of coffee w/a tad of 2%milk and thats all the carbs I get.Now is the caffine preventing the stix's from turning purple but I am in ketosis or am is the caffine actually stopping me from going into ketosis?Im 5'-9" and 172lb's in to weeks only lost about 3-4 lbs..thank you for any advise.