Uy, totally normal yan, mama! Newborns on EBF usually have that seedy, mustard-like poop and they do it frequently, even 6+ times a day is completely okay at 6 days old, so don't worry. A few of us mums sa circle namin, we all had the same worry, pero ang pediatrician assured us it's a sign baby's feeding well and digesting properly. Just keep monitoring that baby's peeing (should be wet diapers) and weight gain, pero otherwise you're doing great!