Blood in baby girls diaper-hormones from mom

My 9 day old just had a small dot of blood in her diaper for the second time (other time was at 6 days old). The pediatrician said it’s normal and hormones left from me from when she was in the womb. It still worries me every time being a first time mom and I’ve never heard of this before. Has anyone one else had this with their LO? How long did it last/how often?