I went through an ordeal today and found myself guessing if my meter was working correctly. I just happened to have a meter than I carry in my purse and a meter that I keep out in the kitchen area. I am glad that I had the extra meters on hand, it probably saved me a trip to the ER. You don't have to buy an entirely different meter and strips, but having a back-up meter on hand might save you some major $$$, especially if you take insulin. Get an extra meter the next time you are out shopping, be prepared.