Low HCG/progesterone success?

So yesterday I was 16 dpo and my HCG was a 21. Progesterone a 4. They started me on progesterone twice a day and want me to come back Friday in hopes that my numbers are in the 80s. 
Has anyone had a successful pregnancy with numbers like this?
I am extremely emotional and stressed because I had a chemical; 9 months ago.