Clearblue digital ovulation tests....

Lindze • LOs: 12/16/10 (Nevaya) & expecting 12/18/15 with baby #2 (Malaki)
What a joke these things are! Anybody else have problems with them? I get an error message on it all the time after I do everything right. Yesterday it worked but no surge the day before that I got an error message and today...error message Grrrr! These we'rent cheap either :( Recommendations on different ovulation tests?? Ones that are super easy to figure out though.