No, trust your body. No child will starve in the few hours it takes to get to a store. Honestly, even the most dedicated people can cave in the middle of the night and you are doubting your supply. It's medically proven that over 98% of woman can breast feed perfectly fine if they had support and don't start supplementing at the first sign of issues. If you dont want to breast feed or wish to supplement, there is nothing wrong with that. But I you are like me and truly want to bf only, have confidence and you can do it fine! Don't doubt yourself. Look at websites like kellymom or la leche for support. And make sure your pediatrician is bf friendly!
But why put yourself under extra stress by having to dash out to the shops, with a hungry baby?
This is my third, and to me, it's just extra motivation to put them back on breast, which will stimulate you to make more milk. I am just my giving honest advice to those who are desperate to have breast feeding work.
Yes, it is stressful at first, and not always easy, but if you can push past the first weeks the payback is huge.
Supplementing, when you want to breast feed, is a slippery slope, and will cause more stress in the long run, to those who don't want to supplement.
As mums to be we put enough pressure on ourselves anyway without having other mums telling us that we have given in too easily, or not trusted our own bodies by choosing to formula feed when BF'ing doesn't work.
Part of successful nursing, for some women, is trusting their bodies but not trusting their minds. Some women can look at a can of formula when the baby is screaming (which healthy nursers will do during growth spurts), and not cave. But I couldn't. So I kept it out. I knew I would cave for an epidural, so I had a home birth. Avoidance does help for some women, for those of us who get extremely emotional and will cave. Postpartum hormones are like pregnancy hormones x 100 during that first week. For me, keeping formula out worked. I begged and cried for my husband to go buy me formula and he kept me rambling until the store closed and it was too late. That ONE night lead to 7 months of exclusive nursing instead of goiing on formula.