Due date help?

Annora • Married 7.12.14 - 3rd Grade Teacher - Baby Goose due 10.4.15
I'm currently 10weeks 3days. I went to the doctor for my first appointment and sonogram about 3 weeks ago. According to the doctor, my due date is October 31, 2015. When the doctor told me that, I was slightly confused. That's seems like too long. I was in the Oct. baby bump group , but their weeks and mine are not matching up, so I thought I'd try here.  If your around 10 weeks right now, what is YOUR due date? Help!?!