I've been feeding my 1 week old pumped breastmilk and she does perfectly fine with it but I'll supplement with formula if I don't have milk readily available. She spits up the  formula. I haven't called my pediatrician because their closed on the weekends.. should I switch her formula? Is she still getting enough even though she's spitting it up? Right now she's on similac pro advance. I have samples of Enfamil formula, 3 different kinds. Can I switch it at her next formula feeding tonight or should I keep trying the similac as it's only been a week? Help! I feel horrible 😖