Worried! Help!

I’m 6 weeks and 4 days. I went and had blood work done because I’ve been spotting(brown discharge when wiping)and having bad back pains. I got my results back for my progesterone and hcg levels. My progesterone is 5.5 and my ob said it should 11 or higher, so he prescribed me Prometrium suppositories. Has anyone ever had this happen and what have you experienced if you’ve had these problems? I’m so worried and nervous about everything! I go to the Dr this Thursday for an ultrasound. Praying for good results!❤️