Can't tell which twin is moving?

Jo

Hello!

I am almost 28 weeks with di/di twins. At my last appointment, the ob asked if I felt both twins moving. I honestly can't tell! Baby B has been in a different position at almost every ultrasound. Last appointment he was smashed up next to his sister. He also has an anterior placenta.

I'm wondering if I'm the only one who kind of guesses which baby is moving at the time?