Spitting up after being fed

My baby is a week and 2 days old and almost every time I feed her she spits all her milk back up after words. She is Formula fed and on Similac advanced. Ive tried to keep her sitting upward after and during a feeding but she still spits up after words. She also keeps acting like she’s chocking on something. She goes back to the doctor Tuesday. Do you think I should wait until Tuesday to go to doctor or call them tomorrow once they open?