Are babies supposed to be puking from 2-3 months after every feeding and still want more when they eat 4 oz of formula? my baby is 3 months old she pukes after every feeding she's been doing that since a month old?

Intermittent regurgitation of breast milk or formula is common among young infants, known as gastroesophageal reflux (GER). Your infant's frequent regurgitation/vomiting can lead to poor weight gain, to induce respiratory symptoms such as wheezing/chest congestion, or to develop esophagitis. Consult with your PCP or pediatrician.

As Dr Park said, GER is a common cause of regurgitation in infants. If your baby is growing and gaining weight, the amount vomited is small, and she is not crying or unhappy with the vomiting, her diapers are wet and she is pooping, and her examinations by her doctor are normal, there may be nothing to worry about. However, it is important to discuss with her doctor and keep up with her checkups.