Small Gestational Sac

I had my second ultrasound last week, in which the baby measured 7w0d, which was about two days behind.  The gestational sac, however, was small and my hormone levels were really low.  The doctor put me on progesterone suppositories (400mg/twice a day) and told me to come back in a week.  I went back today for another ultrasound and the baby has grown a week and has a heartbeat of 142.  The gestational sac, however, is not growing the way it should.  I really am unsure what this means, what my chances are, and how normal this is.  Any ideas?

[peekawho]

I think you have to look more at the positives:  your baby is growing appropriately, and the heart rate is normal.

I'm sure the doctor will keep watching it appropriately.