Baby all of a sudden fussy and irritable

LindseyLooMagoo

My son is 3 months and this week he has been really fussy at night when he wakes up to feed..he kicks his legs and cries like he has gas but we haven't changed his formula that he's been on the whole time.. He also hasn't been sleeping good or eating as much as he does.. I took him to the doc because he has a cold with a bad cough and doc said noting to worry about just a cold.. Why is he being so fussy lately maybe because of his cold? Or growth spurt? Anyone else deal with this