IF i am pregnant, when would i get an extremely BFP? like absolutely no doubts that it’s a honest positive?

my period was nov 4-9

my cycle is usually 27 days

app says i ovulated on the 14, but i have no clue.

had sex in the said fertile week and before the fertile period and also after the fertile period.

my period was supposed to start on the 28th (according to GLOW) (<a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> said i should start on december 3rd) , but still no sign of her, except for my extremely sore and sensitive nipples. but in the past, this has never been a sign of AF. my tests have been negative ( no BFP )

i have read all sorts of reasons for late periods, but no BFP. i’ve also seen that testing a week AFTER my missed period will be a lot more accurate.

what do you think? when should i test?