Hcg levels okay?

I had my first hcg blood test on 1/15 which was 820, I had thought I was 5 weeks 3 days at the time however nurse said it was a little low so probably more like 5 weeks exactly. This past Tuesday 1/22 I had some very light spotting and when doctor did an ultrasound only saw a yolk sac, no baby. I did another blood draw because he was suspecting possible miscarriage and just wanted two back to back blood tests to make sure hcg was rising, blood work done yesterday was 13,200. Does this sound about right? I have another blood draw tomorrow so I should know if things are okay soon. I just can’t stand to wait.