According to my dates I think I am about 5 weeks. But the Can you talk to your GP (or another HCP) about getting that blood test done? I've had to do early GD tests with all of my pregnancies but that is due to prior health issues. There is something seriously wrong with this system of maternity care.
Here is a pic so you can compare to your 6 or 7 weekish ultrasounds. I conceived, but ultrasound only showed I was 6 weeks 5 days. my 1st scan said i was 7wks 4 days but wen i went back for my 12wk scan i wasnt 12wks 4 days i was 13