2weeks vomiting?

Mga mommy ask ko lang po my lo is 2 weeks old palang. Nagfoformula sya at nag bebreastfeed din. Ung 1 weeks nya ok naman sya pero ngaun na nag 2nd week sya.. nagbbreastfeed sya sakin..kapag nag bobottle na sya sinusuka na nya ung nadede nya bakit po ganun? Pero pag breastfeed hindi naman. Pls help. Tia!