How accurate

How accurate would you say glow is? According to glow I should be 6+5 but I had an US Tuesday bc the ER need to make sure I wasn't having a Threatened MC. The tech said she wasn't sure but that it looks like in 5+5. I'm kind of bummed bc I was hoping I was a little further along. She said she wasn't 100% sure though bc it was so early. Has anyone gone through this? According to her calculations my conception and ovulation date were later than I though. Which is weird. Here is what we got when we went