my advice would be not to have them check you or, if they do, not to tell you the results. it's just super frustrating either way.
you could be 2cm and then you'll get all excited that you're 2cm and start to think it could be any day now, then end up going over.
or you could be nothing, then get upset because nothing seems to be happening.
my doctor wasn't going to check me until my 40 week appointment, but i asked her to check when she was doing my group b test at 38 weeks (i think) so she did. it was a big fat nothing! i'd been on bed rest for weeks, i had high bp, signs of pre-e, i was just done being pregnant, then to hear i hadn't made any progress yet just pushed me over the edge. if i wasn't having a c-section with my next one, i wouldn't want to know any of it.