37 weeks preg. 1-2cm dilated 2 weeks ago. self checked, felt oval with rigid brim and interior of oval was like a crater not a hole. is this cervix?

Possibly: It could be, however, it can be hard to accurately gauge the dilation of the cervix even for doctors. Doctors in training often need to do cervical checks a few dozen times with feedback from experienced mentors before they feel comfortable with the accuracy of their measurements. Let your doc know if you're doing self checks and they can give you more guidance on safety and accuracy.