Transverse lie


So my baby has made 2 pretty dramatic movements (one was because I bumped my tummy kinda hard, but not super seriously) and the second is when I was just standing outside. It feels like he moved to the bottom of my tummy, or like he just dropped suddenly. It's very scary and super concerning only because I've never experienced that before. He's moving all the time like kicking and punching but never like that. Could he be flipping to transverse lie? Or upside-down? Does anyone know? Or know what it could be?? I always get scared and sit down. It never lasts more than a few seconds but it's scary! Please help!