no ultrasound at 36 weeks?

Ro
My doctor just told me today that for low risk pregnancy her clinic does NOT due the 36 week ultrasound. Instead thy do a cervical check to feel for the head. If they can't determine by doing the check, then they do an ultrasound. Is this normal?! Mind you this clinic is part of a well regarded hospital in the Boston area. 
All I've ever heard is that an US is done at this point. I was really hoping to avoid a check until I go into labor... also, how can they possibly accurately estimate the baby's weight without an US? Freaking out a little 😟