Hi mommy. Mix feeding ako for my first month kasi naiwan sa NICU baby ko and ngaadjust pa kasi ung supply ko ng milk. Kaso on my part priority ko that time ang breastmilk pag ubos na ung supple that's the time I introduce ung formula. Usually 2 beses lang in a day madaling araw lang sya formula fed(si husband or mother ngaalaga) para I can sleep. In your case na alternate baka nacoconfuse si baby. Mas sweet kasi ang formula kaya mas nagiging prefer nya un.