BabyMD: Fertility Calculator and Ovulation Calendar - Free fertility calculator and ovulation calendar to calculate your fertile days, and help you identify when to expect the first pregnancy signs and symptoms.
FortuneBaby.com: Ovulation Calendar - The ovulation calendar shows the days when you are ovulating which will help you increase your chances of getting pregnant.
Ovulation Calculator - Provides an online ovulation calculator and detailed information on ovulation and pregnancy.
WebMD: Ovulation Calendar - Interactive ovulation calendar to help you determine your most fertile days.