48 hour difference in levels

Je

In 48 hours, my HCG went from 13 to 26. My progesterone went from 8 to 23. I was pregnant in August and miscarried at 8 weeks. My initial HCG levels at that time were 1,070 and 2,300 so I’m a bit concerned. Has anyone had any experience with these low HCG levels? Thanks!!