15 weeks 2 days

A💓C • Married, 33 yrs old pregnant with our 3rd. I haves 2 boys ages (14/8) and praying for my little girl.
I had a sono done last week NOT knowing I was as far along as I was told.... I was 14 weeks 2 days !!!! My question is why does my sono say 12 weeks 2 days? Am i not as far as they say I am?  I am still confused even though they explained to me.