Most women go past the due date until they go into labor. Knowing how far along you are really will not do any good, anyways most women are dilated 4+ cm and still go weeks before going into labor , Checking you also can be a risk for infection the less you fiddle around down there the better.Maybe your next week visit you can ask him/her to check and give him/her reasons why you want to know how far you are . unless he gives you a valid reason why he wont.then just go with it and try to enjoy your last few weeks of pregnancy ! i know how hard it can be at the home stretch. when my water broke i was only 2 inches and was over a week due. i had a long long long natural labor.
sorry i thought this said 36 weeks. obviously since your doc said they would check at 40 weeks then hold your doc to it if you really want to know. i never got checked until after my water broke.
With my first and with this one I have been checked at every appt since 37 weeks. Last time it irritated me though and I had horrible contractions that would stop I swear one went on for an hour, but it wasn't labor just pain. Maybe your doc is smart to not check till 40weeks.
even if you're dilated doesn't mean you're about to go into labor. it just causes unnecessary pain. just sit tight