R.Y.
A 28 day cycle is average, but not everyone is average! A 40 day cycle is still in the average range. Stress can make your body delay or skip ovulation (which can make a single cycle longer). The book Taking Charge of Your Fertility has a lot of detailed information if you are interested. You can learn a lot by charting your cycle of a few months. Plus, on the small chance there is a problem, you have detailed info for you ob/gyn to review. BTW, my period got heavier after having children.