Book sign after replacing bettery.
My wife was using Clearblue Advanced digital Ovulation test(20test/2Month supply). She saw SMILE(Peak Fertility) 2days ago and was trying to test it again this morning. She didn't know that it will be displayed for 2days on the indicator. She told me that it was useless because it had displayed smile for 2days. And I opened the case and replaced the bettery. Now I see Book sign all day long. What should I do? Do I have to throw it away and buy a new one? She has 17 test sticks left. How can she use and test them?