7.5 week old newborn sleep noises

Hi there,

My Bub was born late pre term at 35 weeks. He is primarily bottle fed by breast milk, but we do need to top up with formula about 2-3 bottles per day give or take.

There are moments where he seems to sleep fine, other times he is squirming and writhing and making awful noises, almost like he is in pain.

We try and take our time to feed him, by burping and keeping him upright.

He does have a little bit of spit up of white milky semi solid looking stuff and doesnt seem to vomit that much.

Now I’m wondering if it’s something to do with his formula and whether it’s a good time to attempt to use a different one or goats milk?

We are just using Nan OptiPro as that was what he was having at the hospital.

Or is there anything else we can do to try help him? Orrr would this pass and it’s a newborn thing for all bubs.