5wk ultra sound no fetal pole

Salina
I had an ultrasound today at 5wk+1. They were able to find the yolk sac but no fetal pole. My doctor told me to come back at 8 wks to make sure i develop a fetal pole. Any one else ever had this situation? If so did a fetal pole develop or did the pregnancy end in m/c
P.s I had my hcg levels check today as well and it was 3798 is that good enough? 
Thank you very much.