Gassy baby all of the sudden

My little will be 6 weeks old tomorrow. He’s been on nutramigen for about 4 week and it’s been working well (it better be for what we pay for it 🤣) he hasn’t had any issues with gas... until yesterday. I noticed he was farting a LOT yesterday and by the evening, he was obviously uncomfortable from it. Now today it’s the same. He’s very gassy and fussy and he’s normally very content. Anyone else having these issues? Hopefully it’s short lived... I’m just trying to figure out why it’s happening all of the sudden 😏

Picture from this morning when he was happy. I love him so much and it makes me sad when he’s fussy!