Progesterone injections

I'm currently 5 weeks 6 days with my rainbow baby 🌈. In April 2016 I miscarried at 17 weeks just when I thought I had survived the first trimester and it was going to be smooth sailing from there. Since second trimester miscarriages aren't very common this pregnancy is being treated as a high risk pregnancy. They believe the cause of my miscarriage is my incompetent cervix. They have recommended progesterone injects and there has been discussion of cervical cerclage... all of this sounds scary. Has anyone else had any of these procedures?