Reflux or rem sleep?

When I put my baby down to sleep she will move vigorously for a bit and then go to sleep. Sometimes she’ll do this and then wake up. Sometimes it’s after she’s been asleep and again she would stay asleep after or it wakes her up. Just want to see if others babies have done this. So I can know to bring it up during her follow up gastro appointment. Or if it’s just what some babies do.