Spitting up

My little girl is six days old and she went from being the most happy content baby never crying, eating fine, waking up every 3 to 4 hours eat to a cranky baby that’s crying and spits up at every feeding and it seems like she just keeps spitting up more. Should I be concerned?? Why is she spitting up so much? Is it normal? I have an appt for her tomorrow but I’m just puzzled why all of a sudden she’s spitting up so much and that just seems to be causing all these other problems.