Well, your range just from the estimated due date is right in between those guys' dates; the reverse due date calculator says sex on April 17-23 would produce a baby due January 15. That said, how did you get your due date? If it was from a doctor asking when your last period was and putting it into a little cardboard wheel, it isn't going to necessarily be accurate. If it was from an ultrasound, how early in the pregnancy was the ultrasound?