Oh I totally understand that worry, the moment my son's poop changed colour or texture I also immediately started panicking and Googling everything at 2am. With breastfed babies, their poop can actually vary quite a bit depending on what you ate that day, how long since the last feed, and so many other things, so sometimes a one-off change is nothing to fret about. That said, since your baby is still so young and you noticed something clearly different from her usual, it would really be good to bring her to your PD or even the polyclinic just to have it checked out, for your own peace of mind too. Do keep an eye on whether she is feeding well, seems comfortable, and has wet diapers as usual in the meantime. You are doing a great job looking out for her, hang in there mummy.