Help!

BreAnn • Married to an amazing man and mommy to the most handsome little man 5.25.18

My little one is almost 4 months. He has been the best most chill baby. Until now. He is so so so cranky for what appears to be nothing. He fights his sleep,fights his bottle. Fights everything. Is this the sleep regression. Or is the other things it could be? No fever ever. No snotty nose he is chewing a lot but even if you offer him a chewie or cold rag he is still upset. Help