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

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.