Cervical checks at doctors appointments?

An

I’m wondering if doctors typically start doing cervical checks at 17+ weeks? Mine hasn’t yet, and I don’t know if it’s something I should ask for. We had a miscarriage at 16 weeks with our last pregnancy. My doctor assured me that it wasn’t because I have an incompetent cervix, but in the back of my mind I’m still worried about it now that I’m 17 weeks. I like my doctor, but I’ve noticed that she doesn’t always do things that other doctors do. I have my 18 week appointment next week, and I’m wondering if I should ask for one if she doesn’t do it. Or if they’re not typically done. Thanks!