My 6 weeks old is spitting up more then I feel comfortable with. I’m not sure why it’s happening because it’s random. I have her on Similac Advanced Pro and have since birth. She will take 4 ounces and after burping her at the each ounce for the first two at the second she some times spits up it all. Even at points she can take all 4 ounces and spit that all back up as well. She only does it about once a day but it’s so messy and I have to feed her all over again. I don’t believe it’s a sensitivity since it’s not every time and she’s not fussy. I use Dr Brown bottles so I’m lost. Any tips or advise?