when do u know its reflux and not spit up!?

Carolina • 1 fresh successful cycle 2015 ! 15 month daughter via IVF and going thru FET Aug 2017 🙏🏼🙏🏼 1 embryo ready for transfer!
So all babies spit up, right!? so what marks reflux and what is just normal!? i dont want to jump the gun and have dr place baby on meds if it is just regular spit up, or if changing my diet (ebf, somight  need to cut out diary) can make a difference. She seems to spit up some times not at all feedings, mostly when she does is due to not being fully burped, and it comes out like cottage cheese like. Also there seems to be no dismcomfort when ahe does spit up, the one thing that does let me belive it can d reflux is that she does the face of something yucky like ahe ahe has swallowed when just laying down flat on her back... What are dead give aways of reflux!? Did any of u have something elae and my symtpoms!? Helllllppppppp