My monthly cycles are fairly regular, almost always 25 days (never longer, although once in a while, 24 days). My LMP was 11/12, so my due date, according to a 25 day cycle, is Aug. 16. If I go by most due date calculators, it would be Aug. 19, since they go by a 28 day cycle. My doctor said that they just automatically go by the 28 day cycle due date. I know that it doesn't really matter in the long run, but I am choosing to go by the 25 day cycle due date of Aug. 16.
Does anyone else not have a standard 28 day cycle? What due date are you going by? due-date-calculator.com lets you enter in your normal cycle length, and your luteal phase length, if you know it.