Yes, a conception date of around October 23, would make an EDD of 7/16. So anywhere around there. Even if your doctor insists on basing your EDD on your LMP, at least it's in your favor (meaning, you get a few extra days before any worries of 'postdates', etc). It's women with extra LONG cycles who have a huge fight to battle, sometimes.
Mama to ds#1 (7) and a ds#2 (1 1/2)