vaginal ultrasound and nothing

#I’m READY

I am 4w5d and the dr ordered a vagina ultrasound bc I was in a car wreck yesterday. They saw nothing in the Uterus and he doesn’t think it’s ectopic bc they would see something.

I was under the impression by 4 1/2 weeks one should be able to see something attached to the Uterus. The DR doesn’t seem concerned bc my HCG levels on Tuesday was 44 and today 161.

Is it 2 early to see anything?