8 or 9 weeks?

What do you guys think?
Went for my first ultrasound today.. i thought i was 9 weeks and 4 days.
They told me i am 8 weeks and 3 days. They thought that because of the size (a little under 2cm)
But when i started to think later i was like i think that's not possible.. 
cause i have seen that with 8 weeks the baby still has a tail and no arms or legs.
As you can see on the bottom photo there is clearly a foot, and we saw arms waving at the ultrasound and the head moving. What do you guys think? I think i am over 9 weeks. I have to come back in 2 days though because they were not absolutely sure of the due date cause it was a little small. (Sorry if it's not written very good, english is not my first language🙈😂 im dutch)