Girls, the baby is one month and two weeks old, they started spitting …

Girls, the baby is one month and two weeks old, they started spitting up milk yesterday at the pediatrician's visit. I noticed today that the gums on both sides of the far corner are completely yellow. Yellowing like this, have you experienced it? Yesterday, the pediatrician looked in his throat, I don't know if I would have noticed if it had been yesterday...I haven't found anything online about it. Tomorrow we're going to see a surgeon for an examination. I want to show him if nothing is said, then back to the pediatrician, I'm afraid of infection.