New Way to Estimate due date

New Way to Estimate Due date
Carol Wood Nichols, professor of midwifery, developed this.
First time moms with 28 day cycle:
last menstrual period plus 12 months - 2 months, 14 days = Estimated Due Date

Second time moms or more with 28 day cycles;
Last menstrual period plus 12 months - 2 months, 18 days = estimated due date

cycles longer than 28 days: estimated due date plus ( days in cycle-28 days)= estimated due date

cycles shorter than 28 days: estimated due date -(28 days - days in cycle =estimated due date