They only could find a tiny egg sac at my 5 week scan and I was really worried too. but fetus started growing quite fast after! It showed up at my next ultrasound a week later. In the meantime please take care of yourself and eat your folic acid, I know it's a nerve wracking wait but you do your best :)
Its also my first pregnancy but previously based on my menses baby was supposed to be in the 9th week but was only measured to be 8 weeks. Dun worry too much!
Yup dnt worry too much! Relax! :) im alr in my wk 36 going 37!
Jesh Jesh