When my daughter flipped, i felt the same thing you just described.
@Cass_plus_one, sounds pretty similar! My son doesn't tend to move a lot until afternoon/evening, so I'll have to pay attention and see if his kicks have changed. Thanks!
Sounds suspiciously like he turned.
When my son turned it was exactly what you described it was like an Olympic swimmer head of off the side of my belly and just boom it was very intense but I noticed that his kicking went from feet in my crotch to feed in my ribs and that's how I knew he was headdown