Progesterone help

My dr wants me to start taking progesterone pills after i ovulate, however i dont exactly remeber what day after he said. Im picking up my prescription tomorrow and i know of course itll have it on there. But i was just curious does anyone dr have them take progesterone pills after ovulation but before your bfp? If so how does your dr have you do it? Id imagine it would all be kind of the same right?