Please don't wait, find another hospital if they won't do a cerclage for you right away. I have a similar experience and just had my cerclage done on Wednesday at 14 weeks and I'm happy I did not keep quiet but wished I had done more sooner. My worries started at 12 weeks when I started feeling a lot of pressure at my pelvic area and I complained to my doctor who already had me scheduled with the Maternal fetal medicine unit so he noted that they should check my cervix length but they didn't, they were concerned about baby being healthy and not having down syndrome so their main focus was getting me tested for all that and the results all came back good. Fast forward to 14 weeks, still having that pressure down there but when I used the bathroom on Wednesday, I noticed what looked like mucus plug and went straight to the ER, transvaginal ultrasound confirmed I was already dilating at 1.3 cm and my cervix was funneling, had the cerclage done on Friday and the doctor that performed the procedure told me loud and clear we should have done this for you 2 weeks ago which was exactly the time I was raising the alarm. He said everything went well but I'm here praying to God that everything truly goes well with this pregnancy and maybe I should have screamed on top of my lungs that my cervix length should be checked at my 12 weeks appointment. Don't completely trust the providers with your issues, their response may come a little too late. I wish you and everyone of us on this pregnancy roller coaster all the best!