Hey my numbers were low in this pregnancy (progesterone at a 6 with hcg at a 32) when I first found out I was pregnant in January of this year. I had a little bit of brown spotting and some cramps and my fertility doctor put me on progesterone suppositories 400mg 3times a day because my hcg was rising but my progesterone wasn't rising as fast as it should have been. Well luckily shortly after I started the progesterone my numbers rose and my hcg numbers rose even quicker. I am not 36 weeks pregnant with a healthy little girl and have had no real problems since. Hopefully this will be the same case for you! Good luck!
That makes me feel much better. I just found out that my hcg levels rose from 76 to 91 to 127 to 171, which seem pretty low and definitely NOT doubling. I am going for an u/s tomorrow and more blood to check hcg on thursday. I am afraid that they won't find anything in the sac, but all I can do now is wait and see. Thank you for your story!