For some crazed reason I thought it had to be so many days after the missed period. But to be fair, the last time I had occasion to buy one was almost a decade ago. I imagine they have changed a bit since then.
I don't chart. I know when it was supposed to start because it always starts on the same date.
It always starts on the same date...?
If you don't chart your BBT, then you don't know if you're truly 'late'. You may have ovulated a little later this cycle. It happens. It doesn't matter how 'regular' you have been in the past, you'll have the same length cycle until one day, you don't.
If you don't want to test 'early', then test the day after your typically longest cycle. Then do as GM said. Test once a week until you either get your period, a BFP, or you hit CD60 at which point you should call your doctor to discuss the next step.