Formula milk + breastfeed

Hai mommies, Nak tanya kalau baby (4 months +) yang minum formula milk ( karihome) + breastfeed memang kena poo poo hari hari ke? Sebab my baby minum susu karihome + breastfeed cuma akan berak 3 hari sekali. Is it normal? Please help and give your experience. Thanks in advance.