confused on my due date? help

Katie • 20 yrs old ☀️ Leonardo 10.16.18 👶🏻💙

So I had an ultrasound 2 weeks ago and was told my due date was October 21. yesterday I got another ultrasound and I was told the due date is actually October 15. So I would be 8 weeks and 2 days. But the picture I was given said I am 7 weeks 2 days. is the picture wrong? she put the 7 weeks in before I was given the updated due date. thanks to anyone who can help me out