High HCG level but no fetal pole at 6 weeks. Help?

Kaleigh
I went in for a blood draw at 5 weeks 3 days, and my HCG was 13,000... Progesterone 16. My doc sent me in for an ultrasound the next day to establish a due date. The gestational sac is measuring 6 weeks 1 day, and there is a yolk sac but no fetal pole yet. Has anyone experienced this? This is my 4th baby but haven't experienced this with my others before. I'm getting paranoid because I thought baby should have been visible by now. 😞