Stupid question from a first time mom...

Hannah • 💍 married in 2018. 🤰🏼due with our first 11/18! ✝️ loved and blessed by Christ.

I feel dumb even asking this but how in the world do they check your cervix and measure dilation? Do they just use their fingers and estimate the centimeters? Or do they use an actual tool to measure??? Lol 🤷🏼‍♀️🤷🏼‍♀️🤷🏼‍♀️