Progesterone

Breanna • 2 angels with tiny wings up there watching over me.
Today my OB confirmed our worst fear. My hCG levels haven't moved in about five days. I already knew I was miscarrying- that much blood isn't normal- but actually hearing it broke us. Broke ME. I feel like I can't breathe, all the time and I can't stop crying. 
That being said, I'm wondering if it was my low Progesterone levels that caused this. They were only at 6 at the appointment before last, and the doctor said that is SCARY low. Yeah, SIX. On Wednesday I picked up my prescription for 200mg oral progesterone (AK2). On Friday I began to bleed, and I still haven't stopped. 
I've heard progesterone is awesome during pregnancy, that a lot of women have taken it and carried out healthy pregnancies, and that it even helped more than expected. But is it possible that they just figured it out too late and that's why I miscarried 2 days after I began taking it? 
I know this is God's plan, although I don't understand it at all, but I'm just trying to wrap my head around what could have went wrong (I know sometimes you just can't explain it), but I don't ever want to go through this again and it scares me to death. It took us a year to finally conceive and it is absolutely killing me that my body couldn't support this baby that we were sooo unbelievably ECSTATIC about. 
Does anyone know anything about this? I'd really love to hear experiences. And anyone who has experienced a loss, feel free to just rant bc it's late, it's devastating, and I'm here.