makena progesterone shot.

I had my last son at 36 weeks to the day. However, I had an abruption at 28 weeks and almost delivered then. With this pregnancy they suggested the makena shot. My last dose is in 2 weeks 😳 anyways my question is, is there anyone out there who has taken it and if so how soon after did you go into labor. I know everyone's different and every pregnancy is different but I'm super anxious about it and just want to know if anyone went soon after stoping the shot. I heard it take about 10 days to come out of your system.....