2 month old rolling on side while sleeping

[TallGal92]

I think I’m just being a worried FTM but I just need some advice/reassurance.

So my 2 month old has recently started rolling onto his side during nap time. He’ll thrash his legs around in his sleep and turn over. He doesn’t do this at night as 1. I think he has less energy to move around and 2. He wears a sleepbag. I always put him down on his back to sleep as I’m aware of the safe sleep guidelines but if he’s moving on to his side himself then surely he’s comfortable and I shouldn’t disturb him.

Should I let him continue to sleep like this during the day (where I can keep an eye on him) or move him back on to his back?

My little one was a cmpa baby and before we knew and when waiting for the dairy to leave his system, he always slept on his side. If he was put on his back he'd be screaming in pain. We put a pillow behind him so he couldn't roll the other way but he was so much more comfy.

Can you use the sleeping bag for naps too? I do for my little one and find she sleeps better.