Wasted 10 tests

recently I’ve bought the clear blue digital ovulation tests. At first it wasn’t working and would show a stick then a book. Then it would work, then today I was in the shower and missed the time where I could see the result. And when I put it back in it flashed that smiley face! Well I like to make sure so I put in a stick, nothing- error symbols. Then another and so forth and nothing. Back to square one. I made sure I did everything right such as enough urine, face down, laid down on flat surface. And I’m getting nothing now.. kind of a bummer. I feel like I wasted $60+ dollars on this just for half of them being completely wasted..