Possible 4th leap?

Lucy

My babygirl is 18 weeks old and as of yesterday she’s been so cranky, doesn’t want to sleep or stay asleep and clingy. She’s never been a cryer and last night when she woke up to eat she just screamed and screamed until she started eating. I thought the 4th leap/4month regression happened 14-19 weeks? How long will this last? The baby sitter said she’s cried all afternoon 😩 is there anyway I can help her?