My 12 week old seems to be getting up

Bharathi

My 12 week old hasn’t started rolling over from back to tummy, but can roll over from tummy to back. Of late we’ve observed that when he is lying down on his back, he seems to be thrusting his torso upwards and his arms are stiff and up, almost as if he wants us to pick him up.

I’m wondering if this is him trying to sit up? Or is this a precursor to rolling over?