Super low hcg and successful pregnancy?

Hello,

I got a faint positive FRER on Monday so went for a blood test. My hcg came back as 12 so I was told to test again in two days. I did another FRER Tuesday and again today and each time they got darker. I had another blood test today and my hcg is now 16. My period was due to come yesterday but obviously hasn’t started. Is there any chance this will be a successful pregnancy? I’m feeling super discouraged.