Slow Rising HCG Levels

I’m 6 weeks pregnant today. On Wednesday, I went in for an early ultrasound (5weeks, 5days). It revealed what they said was a health gestational sac, in a great location, but no yolk sac or fetal pole could be seen. My HCG levels were 5084. Today (2 days later) I went back in for another HCG test. My levels have only increased to 6293.

I feel like this means I’m going to miscarry, or that the pregnancy isn’t viable. My dr is keeping me on progesterone, and has me scheduled for another ultrasound next Weds. I feel super discouraged.

Has anyone had a successful pregnancy with HCG levels that rise slowly?