Both tests showed error symbol

I purchased the Clearblue digital test this evening and took the first test. I received the error symbol so I waited and then took the second test shortly after. Again, I received the error symbol. Almost $15 for the box and both tests malfunctioned. This is the first time I tried Clearblue and I don't think I'll be using them again. Now I have to go back to the store and spend more money on a different test. Has anyone else experienced both tests malfunctioning?