Your cervix turns a different color when you are pregnant. They can see it. When they are feeling how far along you are, they are feeling the SIZE of your uterus. The size tells them approximately how far along you are.

If you have been studious about feeling what your cervix is like all through your cycles, then you might be able to tell if you are pregnant with cervical position. Unlikely though but remotely possible.

If you think you are pregnant, take a test

yeah they arent feeling the cervix they are feeling the size of the uterus. They can't judge how far along you are by simply touching the cervix it serve absolutely no purpose in regards to how far along you are.