15dpo brown spotting, high BBT - When should I test?

I was supposed to start AF yesterday at 14dpo. BBT was high and only very light brown spotting in the morning. Did a pregnancy test and got a BFN. Today is 15dpo. Same very light brown spotting as yesterday, same high BBT.

Only discernible, consistent symptom for the last week is sore breasts.

If AF continues to not come, when do y’all think I should test again?