Knowing when your babies are repositioning

Felt a ton of pressure on my sides two days ago (that's the best I can describe it), and of course got a little worried, but my first instinct was the twins have to be repositioning. Sure enough had my doctor's appointment yesterday and they did an ultrasound to get the heartbeats, and where one twin was head down before and the other breach, they were both transverse. So THAT explains the pain I was in that night. Very uncomfortable lol