When Are You Most Fertile?

• You ovulate about 14 days before the start of your period.
• You are most fertile in the days around ovulation and least fertile just before you menstruate.
• During ovulation, your basal body temperature will rise by about 0.5 to 1 degree Fahrenheit.

If you are trying to get pregnant, timing matters.

Your chances of getting pregnant change through your menstrual cycle, so it’s helpful to track your cycle when trying to conceive – or when trying to conceive.

Typically, a woman’s menstrual cycle is 28 days long, says Mary Jane Minkin, MD, an OB-GYN at Yale University. However, this is just an average – some women have a longer cycle, while others have a shorter one.

Regardless of the length, your menstrual cycle begins on the first day of your period, so it is helpful to have regular menstruation if you want to track your cycle. If you have irregular periods, it can be harder to tell when you are ovulating.

You will probably get pregnant in the five days around ovulation

“The most fertile time of your cycle is right around ovulation,” Minkin says.

During ovulation, you release an egg from your ovaries into one of your fallopian tubes where it can be fertilized by sperm. But if that egg is not fertilized within 12 to 24 hours, it breaks down and dies essentially.

However, the time when you are most likely to get pregnant is longer than 24 hours. This is because sperm has a longer lifespan and lives in a person’s body for 3 to 5 days.

So, “if some sperm are deposited a day or so in advance [of ovulation]it’s good, ”says Minkin, because the sperm will still be around when the egg is released.

Therefore, you will probably get pregnant if you have sex in the five days around ovulation and the day of ovulation. But do not overdo it.

If you have sex too often, the amount of sperm in each ejaculation may be less concentrated and “it may not be as effective at getting you pregnant,” Minkin says. Once a day, or every other day, seems to give the best results.

You are least likely to get pregnant just after ovulation

You are least fertile when you are furthest from the time you start ovulating.

So, right after ovulation, in the days just before your period – is the least likely you will get pregnant.

It is possible, but not very likely, to get pregnant during your period, especially if you have a short menstrual cycle and ovulate early.

If you have sex the day after your period ends, it is possible to get pregnant because the sperm may still be present when you start ovulating about a week later.

How to tell when you ovulate

Since it is such a small window, it can be difficult to pin down when you start ovulating. Here are some tips:

• Follow your cycle: To get started, try to keep track of your cycle. Ovulation occurs about 14 days before your period begins. Count back from when your period is expected to arrive to find out when you should ovulate. If you have a 29-day cycle, you will ovulate around day 15, but if you have a longer 35-day cycle, you will ovulate around day 21, Minkin says.
• Monitor your cervical fluid: When the texture is creamy and the color is white, it indicates that you are approaching ovulation, and when the liquid becomes smooth, stretchy and clear, it is a sign that you may be ovulating.
• Take your temperature: Another strategy is to take your basal body temperature, which is your body temperature at rest. Measure it in the morning, when you are still in bed, before eating or doing any activity. During ovulation, your temperature will rise slightly, by about 0.5 to 1 degree Fahrenheit.
• Ovulation predictor kit: The most accurate way to predict ovulation is with an ovulation predictor kit, says Minkin. These over-the-counter urine tests are available at pharmacies and detect the presence of hormones that indicate ovulation. Minkin recommends the First Response ovulation test for its accuracy and ease of use.

She especially recommends an ovulation predictor kit for people who are older or have been trying unsuccessfully for several months. “If you’m 25 years old, newlyweds and would like to have a baby – no, you do not have to start with an ovulation predictor set – go enjoy it,” she says.

Insider takeaways

You are the most fertile in the five days around ovulation. To know when you are ovulating, you can monitor your cycle, monitor your cervical fluid, and use methods such as an ovulation predictor set.

Fertilization may not occur immediately, but it should occur within 6 months to a year of consistent efforts. If you are under 35 and have been trying without success for a year, Minkin suggests that you consult a gynecologist. If you are 35 or older, you can sign up sooner, as early as six months.