If you try and flex your core, or if you lean back just slightly and you have a "wedge of cheese" at the top of your belly, you likely have some degree of separation.
I had no idea I had it until a few months pp. I went to the OB for a check-up and asked why I still felt so puffy above my c/s scar. She made me do the test and confirmed I had diastisis on the bottom two abs. The top half were still intact.
Re: How do you figure out if your abdominals are separated?
I googled this to find out what it even was.. i keep learning new things!
https://postbabyfitness.blogspot.com/2010/02/do-you-have-abdominal-separation-or.html
and a self test to see if you have it:
https://postbabyfitness.blogspot.com/2010/02/test-for-diastasis-recti.html