Stop stressing -- most likely everything is just fine. Almost all babies have gastroesophageal reflux (GER), usually just called reflux. "Seventy percent of infants under 3 months will spit up three times a day, and it's even perfectly normal for them to be spitting up as often as 10 or 12 times," says William Byrne, MD, chief of pediatric gastroenterology at Doernbecher Children's Hospital, in Portland, Oregon. The most common reason is that the muscle at the bottom of the esophagus, which opens and closes to let food into the stomach, is still very weak at this age -- so it's easy for stomach contents to escape and come back up. Your baby is most likely to spit up after a feeding, but this can also happen when she cries or coughs forcefully.