Due date Question

So I just had my first sono on Oct 31st... the sono read 7 weeks and 4 days... my sono tech told me that the due date would either be on June 10th or June 15th... when I seen my doctor he said I was 7 weeks 4 days and was due June 10th.... if I do that due date on this app it says I'm 9 weeks and 1 day... but from what my doc told me I'm 8 weeks and 3 days today... I'm so confused... which should I believe?