Prenatal screening

Lacey • Mommy to an Angel 1.14.16; wife 9.24.16; rainbow baby 4.4.17 && Baby #3 Due 4.28.20
So I had the first round of the prenatal screening (Down syndrome and spina bifida). The ultrasound tech printed some pictures and it said that I'm 13 weeks 3 days. Which might be wrong because today I'm 13 weeks. So why would it say different on the pictures?