Talk to Dermatologist on Incompetent Cervix

Asking for Self, Female, 38 years old, LAHORE

I am 20 weeks pregnant. This is my second pregnancy. The previous one was miscarried at 18th week. It was due to the bursting of amniotic sac. I have cerclage during this pregnancy. Last night, mucous plug came out and pre term labour pains started. Now I am taking nefidil with few hours gap and pains have settled for now. This is my anomaly scan which I had today. Please tell me what are the chances