How long after conception can you find out if you are pregnant?

I found out at 13 dpo. with a faint positive hpt. But doctor say to wait until your missed period or 8 days after your missed period. According to the ClearBlue pregnancy test accuracy results they are: 4 days before expected period= 51% accurate

3 days before expected period= 82% accurate

2 days before expected period= 90% accurate

1 day before expected period =95% accurate

the day of expected period =99% accurate