Progesterone Suppository

About 23 weeks pregnant I started getting cervical checks due to history of colposcopies and a leep procedure. At 27 weeks pregnant my cervical length went from 3 cm to 2.4 cm. so it was suggested I start using crinone 8% suppository. My insurance company denied the medication 3 times. At 28 weeks my cervix measured 1.8 cm. paying out of pocket I bought the gel myself. Has anyone else had this problem and been put on this medication before? Was it successful? I'm 29 and 2 and I go for my next cervical length on Tuesday hoping this medicine has done its job. Keeping fingers crossed