Some babies spit up a lot. It's only a problem if acid is coming up and burning her throat. Mine all had reflux. For the most part they seemed to suddenly get fussy at around 10 days old. (Before the diagnosis), I thought my son had trapped gas and spent I don't know how long trying to get a burp out of him. When he finally burped, he actually cried a little harder :( Also the back arching, and unconsolable crying were what they went through.
Talk to your pedi- although he/she may have you change formulas 1st to see if that helps- like lactose free or Nutrimigen. It was really frustrating because we had to wait 2 weeks with each formula change to see if it helped. It dragged the whole thing out so much, and, while I understand them not wanting to give unnecessary meds, it's so hard going through the sleepless nights and all the crying. It made me feel helpless to see my baby hurting, and not be able to help. There were times I was tempted to offer to drop my baby off at the pediatrician's house for the night so he could see what it was like!! :/
With our 2nd and 3rd, we went straight to Nutrimigen after the fussiness started (they started on lactose-free at birth) 1st to save all the back and forth trips. Once they got the medication, they were so much better!
Hope your DD feels better soon!! :)