HELP FTM!! gassy fussy uncomfy baby!

I pump and give breastmilk to my 7day old during the day + some formula and then formula at night. He tolerates everything well during the day - he eats, burps, sleeps. But last night, he was very fussy and passing gas and just uncomfortable. Finally at 3am, he fell asleep and was okay all day. Today at 9pm after his feed (breastmilk), he was being fussy and uncomfortable again... he did not want to sit and be burped, he did not want to do tummy time, he did not want to lie down - he was just squirming and uncomfy. I changed his diaper hoping to give some relief but to no avail. Finally i gave him a binky (which i was completely against...) but sucking on that he fell asleep. I am so confused! Is it my breastmilk thats problematic or the formula? Or is it just gas at night? Why at night tho? :-/ please share some insight!