Smiley face on an OPK

[Bumpwanted]

So am having a go at testing using clear clue POK sticks with the smiley face (much cheaper on Amazon fyi).

I was stuck in a traffic jam on Sunday and so didn't end up testing as ended up being desererate for the loo in the services before I could get back home to the sticks so messed up the testing slot!

I tested the day before and today and no smiley face. If you get one, how long do the hormones hang around to keep a test positive?

I.e. if you get a smiley face on day 14 will you also have one on day 15?

Could yesterday have been smiley face day and I missed it!?

I think they're really hit and miss. I've tested twice on the same day before and got a smiley face one time and not the other. Actually, I used OPKs for about 3 months on and off (out of 16 months of trying) and only ever got 1 smiley.
Try not to get too hung up on them, I think you can end up relying on them to tell you when to have sex, but then not get a smiley and have missed the window.
My doctor also told me that you won't necessarily ovulate the same time every month either.

Yes, you may have missed it, but it may be that you haven't ovulated yet. Like ruthie said, you don't necessarily ovulate the same day on your cycles each month. Mine go between 11-14 CD. I've always got a positive and to begin with I used to stop testing as soon as I got a smiley, but for last couple months tried again just out of curiosity. First month got a smiley once, next month got it twice. Just keep trying for a few days and suggest you keep up the SWI!

assuming you have a 28 ish day cycle, could it not just be easier to have smi every ither day from day 10 to day 20? o am i missing something? these sticks seem lke a pain in the arse- i never get a positive, must be missing it

My doctor recently told me that people often ovulate earlier than they think and he recommended doing it every other day from day 7 to 20