Breastfed baby. I have a crack in my breast and she drank a little blood. She regurgitated it yesterday. Is it possible for it to end up in her diaper?

Yes, it is possible that blood from a cracked nipple could end up in the baby's spit-up or even in their diaper. Barring any other complications, the presence of any black filaments should stop within 48 to 72 hours after the bleeding has stopped.