Cervix checks? Need feedback

Paige • 20 years old. Blessed with twins, due date set for July 14th 2016!
How far were you ladies with twins when your doctor started to check your cervix? Also when did you and your doctor start to discuss about setting a sooner due date considering twins are full term at 36/37 weeks? 
I will be 33 weeks 6 days on wedsneday and I have another appointment but only to monitor my babies hearts for 20 mins each and that's it. My last appointment at 31 weeks or so I asked my doctor when would we start to discuss birth and figuring that all out and she said she "wouldn't know" until I'm 36/37 weeks but I will be full term by then I feel like we should be talking about all that now...  My true due date is July 14th but I will be full term around the 15th of June or so. Iv had a great pregnancy so far no complications or serious concerns/worries at all.