Low progesterone

I am freaking out. I am six weeks two days. I had a progesterone draw two days ago and my levels came back at 8.2. First trimester should be 11 or higher. Anyone have any experience with this and not lose the baby?I posted in this group to see if anyone had been through the same thing. I did have a scan two days ago, saw sac and egg yolk. I am already taking a progesterone pill, 200 milligrams, once a day. I contacted the nurse line, and they said to just continue the same dose until next Thursday when I have a scan. I'm feeling like I should just prepare myself for the worst.