Fertile times?

Originally Published: February 1, 1994 - Last Updated / Reviewed On: July 20, 2012
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Dear Alice,

When can a woman, during her menstrual cycle, be at high risk for pregnancy? I've heard two answers: fourteen days before or after your period. Which is it?

—Conceiving only ideas

Dear Conceiving only ideas,

If every woman’s ovaries worked like clockwork, the egg would burst from the ovary (ovulation) approximately two weeks before the beginning of her next menstrual period. Around ovulation is a woman's most fertile time. Therefore, a woman can become pregnant by having unprotected intercourse up to five days before ovulation. A man's sperm can survive in a woman's body for 3 to 5 days, and hang out and wait to fertilize the egg during ovulation.

However, it is important to know that the above formula is only true for a woman whose cycle is exactly twenty-eight days long (something that cannot be known for certain until that particular cycle is over and menstruation begins). Therefore, guessing how long your period usually is and counting backward fourteen days is not an effective method of birth control.

If you are trying to figure out exactly when you ovulate, you’ll have to pay extra special attention to your body. The fertility awareness method of birth control (a studied, standardized monthly procedure), can help women figure out when they are ovulating. It is a multi-pronged process, involving counting days, observing cervical mucus, taking daily body temperature measurements with a basal thermometer, and carefully charting all of these observations. Given that this method requires a lot of time and energy, it requires a highly motivated person.

On the other hand, if you are looking to avoid conception, it is important to remember that the only 100% effective way to avoid pregnancy is to not have sex. But if you are sexually active and want to avoid pregnancy, your best bet is to find the optimal form of birth control that works for you. There are a myriad of contraceptive options. These range from hormonal methods such as the birth control pill, to barrier methods such as the male and female condom, to intrauterine devices.

If you would like to learn more about birth control, it may be helpful to speak with a health care provider. Columbia students can make an appointment at Medical Services through Open Communicator, or by calling x4-2284. Hope this information leads to a conception — of knowledge, that is!

Alice