If she was born yesterday, it's perfectly normal for your milk to not have come in yet.
Are you still in the hospital? Is your daughter in the nursery?
My oldest had low glucose when he was born. I nursed him right after he was born, but the levels were still low and he was taken to the nursery and given formula. Because I told the nurses I wanted to breast feed, they had me pump every 3 hours while I was in the hospital. My son was in the nursery for 10 days (other issues, not just the glucose), and once my milk came in he was fed bottles of breast milk rather than formula.
Try to relax (I know, easier said than done), and pump every 3 hours. Try not to worry about breast feeding right now. You absolutely have the right attitude that if she needs formula, she gets formula. Once she's overcome this hurdle, you can work with a lactation consultant if she has any trouble latching on.
But for now, I would pump so that your milk does come in and comes in strong!