Combo breast/bottle feeding

Hi ladies just wondering something. I plan to breast feed my daughter when she’s born in 7 weeks. I know sometimes it takes a while for ur milk to come in so obvs I have bottles and formula milk to start her off on if this is the case. BUT what I want to know is can i switch between formula and breast feeding? Like so my partner can feed her formula milk if I can’t express any (I have an electric breast pump I plan to use but never used one before) (I breastfed my son for a couple of days when he was born ans then switched straight to formula because he was tiny and I didn’t like not knowing how much he’d had to eat, this was 7 years ago now so I’m a bit outdated).

Any help much appreciated.