Could my 15 month old be potty training himself?

For the past few days my 15 month old has been going over to the diaper drawer, grabbing a diaper, handing it to us and lying down for a change all by himself. He always has poo in his diaper when he does this.

He only has a few words (we're teaching him two languages, so there's a bit of a delay, but he understands both languages) so I really don't want to train him yet as he doesn't know any words related to the topic, but I've been working in ECE for nearly 15 years and have never seen this kind of behaviour so I'm curious if this is normal.