Cervical Cerclage

Friday I'm seeing a specialist about my woman parts. I saw my doctor yesterday & my cervix is measuring a good length & it's closed. I'm only 8w3d.. I'm having my second set of twins though & since I was never given to reason for my first preterm labor at 22 weeks I'm getting my cervix checks for incompetence.. My doctor mentioned the cervical Cerclage to me & as well on the paper to the specialist.. I've done some reading on it.. Good & bad things & I'm just so nervous & afraid.. Since I'm urgent I'm being seen before 9 weeks but I've read it cannot be done until I believe 13 weeks.. Have any of you woman had this done??? Can you please share your experiences with me.. Thank you.