How were you able to donate blood to your Dad?
When my dad was in the hospital and needed a blood transfusion, the hospital asked if he had any relatives that were willing to donate. I was the only one with the matching type so I went straight down to the blood donation center and donated - within a few hours, my blood (it was marked as mine) came up in a bag and hung up on his IV.
He had no reaction to it, as he’d had to other donor blood.