When should I test ?

I got my period on December 5 an according to my obgyn I ovulated approximately on Saturday December 16 , CD12.

I have a blood disorder so I have know asap if I’m pregnant.

I will go do blood work but also was wondering when can I start testing with home pregnancy tests ?

I’ve seen some ladies testing on dpo 8 which would be not even 3 weeks “pregnant”but I’ve seen faint positives and 8/9 dpo.

Any help advice would be appreciated!