Newborn Poop

Jill • Married • 35 • PCOS Daughter born 23/09/2015 Daughter born 27/03/2019

My baby’s poops are all very liquidy. She is three weeks old. Is this normal for a newborn? She isn’t fussy after eating and sleeps well. She spits up a bunch and often gets the hiccups. I’m just wondering if the liquid poop is normal at this age or if I should be concerned about the formula upsetting her stomach. We use similac advanced and she had a feed or two of breastmilk a day. Should I look in to switching to sensitive? Thanks everyone!