Any suggestions?

So the past two days my almost 3 week old has been projectile spiting up… Any suggestions? I don’t believe she’s over eating by any means.. highly concerned because she has acne on her face but her doctor said to watch it to make sure it doesn’t get and I quote “mean looking” because then it could indicate a milk allergy.. there just on her face and she doesn’t always projectile.. what do I do? I’m scared somethings going to happen to her if she is having a allergy issue with the formula and we keep giving it to her..