They usually check at 37 or 38 weeks
Its appears to depend on doctor country and individuals.
I've been checked three times so far (not for dilation), but for to make sure I'm still closed etc. As I'd a prem bby before. I'm 21weeks.
I think my doctor likes me ;) because I see no reason to check unless there is discomfort or something.
To check they literally put their gloved finger/fingers into you and feel around :/ not very pleasant
I live in austin Tx. And thank you ladies (: