Diastasis Recti?

Gabi

So I’m 25 weeks pregnant and today I noticed my abdomen doing a strange thing. When standing upright, my belly is nice and round and pregnant. When I lean back (as if flexing my abs), the sides of my abdomen cave in, leaving only the center of my belly poking out. Is this a symptom of Diastasis Recti? There’s no pain involved. I just noticed the strange shape it was making and became curious. Has anyone else noticed this while pregnant?