Changed due date?

Lauren • Mommy of 4. 👧🏽👧🏽👶🏽👼🏽

So when I did my calculation I originally thought my due date was July 12. When I went to my 8 week check up they told me my due date would be July 19th. Just went to my appointment and they are now saying the end of June first week of July. Anyone else have this big of a difference from the original due date?