Fussy 3 month old

My son will be 4 months next week. For the past couple days, he seems to be fussy for no reason. When we put him down to play he cries to be picked up and walked around.

I had a thought that he could have an ear infection- He has one ear that is red, his cheeks are reddish, but I’ve checked his temperature multiple times and it has been normal. He is also sleeping through the night.

Is this just something that goes away, or should I call the doctor?