Threaten miscarriage ?

So my OB said I’m at risk for threaten miscarriage because my hcg is rising very slowly and my progesterone at 7 weeks was only 6.7. The OB office calls me every 3-4 days asking me if I have any bleeding or severe pain. We saw baby on ultrasound with a strong heartbeat at 7 weeks. What exactly does this mean? Does this mean I’ll miscarry? What are the chances I won’t? I’m already taking progesterone pills. Started a few days ago.