L.G.
My daughter spit up a lot when she was very young. It wasn't due to me nursing her but it was something under-developed in her system that didn't keep the food down. They probably have a name for it these days. We had to position her differently to allow gravity to help keep it down. Keep breastfeeding unless the doctor tells you otherwise. Not only is it a huge savings, but there are so many other benefits.
Because it seemed like may daughter was spitting up so much and she was a small child already, I was concerned (and so were so many older ladies, including my mother-in-law). But the doctor said it was not a problem because she was still gaining weight. So I would reassure these other well-meaning ladies, that "my doctor said..." That always works well when you get unsolicited advice or concern.