Drop in hcg

Anyone had a drop in HCG between 6 & 7 weeks?

Went last Tuesday for my first appointment. I was only 6 weeks so they were only able to see the yolk sac. They took blood as well and my HCG levels were 32,467.3.

I went back today for another blood draw and my levels were 21,309.9.

I haven’t heard from the dr. yet but wondering if this is normal? Everything I see says it should have increased dramatically.