Baby chewing/choking

Does anyone else's baby act like they are chewing on something or choking on something? Its been happening recently while she's trying to sleep. She makes a sound like she's trying to spit up something and is choking on it. When I sit her up right to pat her back and help her out she only spits up what looks like clear spit. She doesn't spit up much at all so I really have no clue whats going on. It freaks me out cuz when shes laying flat on her back she sounds like she is struggling to breathe until I sit her up. After shes done choking and trying to spit something up she looks like she is chewing on it. Again, I've looked in her mouth and it doesn't seem like there is anything in her mouth. My firsr thought is that it is some type of acid reflux issue. Anyone have any ideas??? She will be going to her 2 month appt on Thursday this wk and will bring it up to the dr. I am going to try to record it as well.