You should get 'taking charge of your fertility' book, it has everything in it you need to know!!! Also, I use OPKs instead, the cheap ovulation tests, as you can see the line getting darker the closer you are to ovulation, as sometimes you can miss your smiley face surge by just a few hours, once my OPKS didnt seem to be getting darker at all, I tested at 4pm and it was faint, and then again at 9pm and it was totally positive!!!! Worth looking into maybe?