I've encountered this too. Moms that suddenly have contractions on top of each other, they are throwing up, I'm excited that we are getting somewhere and then they are checked and have made no progress.
: I've never really tried to rely on patterns because they are SO different for each woman but I still admit, I try to guess...and a lot of times I'm wrong.
I'm convinced it's because hospital settings aren't ideal and moms have a hard time really relaxing so their tension and anxiety is not usually due to the progression of labor but due to the distractions in the hospital and their fears.

I'm convinced it's because hospital settings aren't ideal and moms have a hard time really relaxing so their tension and anxiety is not usually due to the progression of labor but due to the distractions in the hospital and their fears.