Confusion around supply, cluster feeding, and pumping

Baby is about a month old. We had to triple feed the first two weeks as she’d fall asleep at the breast due to being 2.5 weeks early and jaundiced. She will now latch and breastfeed for 10-20 mins per side but I have a lot of confusion and frustration that stems from our earlier feeding challenges.

During the day baby will breastfeed usually every 2-3 hours, but sometimes will cluster feed with smaller durations like 30min-1hr in between. Sometimes she’ll get formula during the day especially if we’re out of the house, but I’m trying to primarily breastfeed her during the daytime. At the end of the evening around 10-11pm she will typically get a bottle of either formula or pumped milk from my husband so I can get some extra sleep for the night feedings. This usually tides her over to sleep for 4-5 hours. Before my bedtime I will also pump to substitute for the fact that she gets a late night bottle.

Before that late night feeding baby tends to cluster feed. Last night I attempted to breastfeed her around 10pm when she’d usually get a bottle (after a bout of cluster feeding in the evening), and she started to cry and fuss like she wasn’t getting enough. When we gave her a bottle she promptly chugged about 110ml. I pumped while she was getting the bottle and only yielded around 20ml since she’d been cluster feeding all night. If she’d breastfed only I imagine she’d have been up every hour all night, but since she got a big bottle of formula she went on to sleep 5 hours.

What I can’t figure out is whether my supply is substandard or if it’s actually just a benefit of formula/bottle feeding that we were able to provide her more food in the evening and let everyone get more sleep than we would have otherwise. My pump yields are larger if I wait longer after she feeds, but it feels like a catch 22 to pump after a longer period of time because then there isn’t enough left to breastfeed.

Baby has gained “just enough” weight per our last ped appt but the doc hinted that maybe we should be giving her more formula which was confusing. It feels like she is getting enough most days because she’ll take 1-2 hour naps, has good diaper output, and I think she would be more fussy if she were hungry. Overall I’m just feeling a bit lost around whether baby is eating enough and if my supply is good enough for her. I’d love to eventually exclusively give breast milk (pumped or not) and cut out formula, but it doesn’t feel possible right now to have enough of a supply to pump for that last big bottle every night.

Would love to hear folks’ thoughts, tips, and similar experiences, thank you!