due date off? help.

Ariel
My period due date would be Valentine's Day. 2/14/17 
Her measurements are due date 2/5/17. (She is a big baby) 
My doctor changed what he told me and said 2/17/17, I corrected him, he stated well it will probably be around valentines- I'm doing vaginal (as long as everything is good) and reminded him that her measurements are ahead and my period was a guesstimate. He kinda blew me off about it- from experience moms- what does this look like? 2/5? 2/14? 
Third pregnancy in a year- 1st was late term
Miscarriage in L/D 
2nd was early loss 
3rd is this one- successful and healthy