Ask The Expert
February 21, 2012
Yes, you could get pregnant at the very end of your period.
The most fertile time of a womans menstrual cycle is the few days just before and after ovulation. Ovulation usually happens 14 days before the first day of your period. If you have a regular 28-day cycle, ovulation happens in the middle of the cycle (about 14 days after your period starts).
However, if your cycle is longer or shorter than 28 days, its harder to predict when you will ovulate and be most fertile. If your cycle is very short and your period lasts for 5 to 7 days, conception could occur from intercourse during your period.
One type of contraception is natural family planning. It depends on not having sex during the most fertile time of your cycle. The length of the fertile time depends on the life expectancy of the sperm (usually 2-5 days), the egg (1-3 days), and the changes in the timing of ovulation. There are even smartphone apps for calculating the most fertile phase of your cycle. One calendar method is to track it like this:
If used alone, this method has a contraceptive failure rate of about 25 to 40%. But you can improve this rate. Use this method while also taking note of other signs of ovulation such as basal body temperature and cervical mucus changes.
The chance of getting pregnant goes down with age. But if you are trying to avoid pregnancy, you should use contraception right up to menopause.