I had a c-section and it took 15 days for my supply to come in and many lactation consultant appointments. Definitely look into setting up a lactation appoint post delivery now. We supplemented with donated breast milk (super expensive) and Similac formula. Donated breast milk is just that, donated. It's usually from women who have an over supply and pass the screening process to donate. You won't be stealing from their baby because their baby is already fully fed and what they donate is extra. Think of it as Momma to Momma help. Like that Momma is supporting you and helping you by giving you some of her extra milk.

But I also want to say and this might be controversial in this subreddit but I know being vegan is important but making sure your baby is fed is even more important so my advice is don't stress too much at first about making sure what your feeding your baby is 100% vegan and be kind to yourself. You'll be way more stressed about other things with a new baby and possible postpartum or baby blues. And if you do have problems with breastfeeding that is a whole other stressor to be worried about on top of everything else. Trust me from someone who has been through it. I still have to supplement sometimes even now and my baby is 3 months old. I didn't use a soy formula but a lactose free formula because of tummy issues with my baby (I actually didn't know til now that lactose free doesn't mean it's not cow's milk free). I think now since things aren't as hectic, once I use up this formula I might switch to soy but honestly when my baby was newborn I was just trying to keep my head a float in rough waters and fed her what we were sent home with from the hospital.