4 losses hcg concerns please help!

hmmk

I have had my hcg drawn several times now due to 4 losses in the past. I have no living children. My hcg started off around 4 weeks at 112, then had a rise after 48 hours to 261. After 4 days I went back for another quant test and the results came back at 1721. I was absolutely ecstatic for a good rise and so hopefully for myself this time around because it is the first time i was able to get on my medication this early! I am on progesterone suppositories 3 times a day and a baby aspirin in the morning. After the last blood test i went back a little less than 48 hours later, just to make sure things were going ok going into the weekend, and they did rise, however, the increase was to 2159, so clearly not a doubling rise. I am currently 5w3d. No spotting or cramping. Has anyone had this happen where their number rise, but not close to a doubling number and continue to have a successful pregnancy? Anyone had this happen and it was the start of a loss? I am just consumed by this at the moment, i am trying not to let my stress overwhelm me but any comments would be so appreciated! I would love to hear from you ladies! TIA!!!!