Baby Poop

Hello mga mamsh! Just want to ask if anyone of you had an experience like mine. My LO is mixfed until nagstop na ang body ko to produce milk. 3 months na sya now and on formula milk for 2 weeks na. She's using S26 Gold since day 1 but started to have this dark green poop nung magstart sya ng pure formula. Any experience on this po? Sa Monday pa po kasi clinic ng doc nya eh. P. S: Hindi po nagtatae si LO. Simula nung mag 2months sya madalas every 2 to 3 days bago sya magpoop.