Mommies, who knows, when I pick up the baby, he starts arching his bac…

Mommies, who knows, when I pick up the baby, he starts arching his back and head backwards, as if he wants to look around, while crying. It's never been like this before, but it appeared a couple of days ago ??‍♀️ Yesterday I couldn't bathe him, he was all arched and screaming ??‍♀️