anyone have an ultrasound from 5 weeks?

Al
My dr said I'm estimated to be 5w2d and there was just a sac there. From everything I'm reading I should have seen a tadpole looking thing in there. Should I be worried? 
Edited: to say that my dr said it was normal to see this but everything I read said i should have seen more. I only had an ultrasound this early bc we had no idea how far along I was bc I have irregular cycles.