My baby's poop is greenish black is it normal

My baby is 2 months I just took her on Monday for her shots and they said to give her Tylonol if she's fussy so I did for 3 days with only 3 doses a day now her poop is dark green almost black she is formula fed the formula is with iron but her poop was yellow until I took her for her shots I'm not sure if it's normal I stopped giving her Tylonol today her poop is still greenish black she's happy but I'm just worried and wondering what it could be