Incorrect Instructions?

I purchased a 5-pack of Clearblue Digital pregnancy tests. The instructions included in the package said to hold the test in your urine stream for 5 seconds, or to dip it for 20 seconds. I dipped two of them for 20 seconds each (timed) and they both gave "Book Error". I tested a third time and dipped it for 30 seconds, a full ten seconds longer than instructed to, and this one finally gave me a clear result of Not Pregnant. Either your instructions are incorrect, or your company has done this with the intention of selling more tests. Either way, I spent $18 for the 5-pack, and will only get a real result from three of them.