When are you most fertile?

Conceiving "naturally" does not mean leaving everything to chance. Understanding your body's fertility signals can help you conceive faster.  The timing of ovulation is complex and can take some studying of your body and your cycles to figure out. 

Ovulation calculator

First understand your menstrual cycle

Before you understand your fertility signs, you need to understand your menstrual cycle and the changes it causes in your body.  Here are some facts.

The menstrual cycle starts the first day of the menstrual period and goes on till the first day of your next period.  Most Indian women have a 28 day cycle. But it can also range from 25-35 days.

First part of your cycle: 
The cycle starts on the day you start your menstrual period. This is the first day of the menstrual period.  Menstruation is the shedding of the inner lining of the uterus when a pregnancy does not occur in the previous cycle. Your hormone levels (Oestrogen and Progesterone) are very low during at this time.  As your cycle proceeds, your Oestrogen level starts rising and peaks about 24 hours prior to your ovulation.

Ovulation:
Oestrogen triggers a release of an egg from one of the ovaries. This is the start of ovulation. Once an egg is released, it can be fertilized for approximately 12 to 24 hours. This is your fertile period (highest likelihood of conception). This occurs typically any time during day 11-21 of your cycle (based on the average 28-32 day cycle). During the time of ovulation, an egg is available to be fertilized for only about 12-24 hours. But since sperm can live in the body for 3-5 days and then the egg is available for one day, your most fertile time is considered to be about 5-7 days.

Last part of your cycle:
Following ovulation, oestrogen levels drop and progesterone rises and becomes dominant for the next two weeks. Progesterone causes the uterine lining to mature, becoming more compact, so that it is able to support and nurture a fertilized egg. If implantation of a fertilized egg does not occur, progesterone levels drop, causing the onset of menstruation, within 48 hours (typically around day 28).

Which days of your cycle are you most fertile? (Fertility Signal)

Your fertile window (the period when you are most fertile and when you are most likely to conceive) is when you ovulate.  Most women ovulate anywhere between Day 11 - Day 21 of their cycle, counting from the first day of the menstrual period.  The first day of the menstrual period is defined as the first day a woman starts bleeding.  The 11th day is most likely the earliest day a woman will ovulate. The 21st day is most likely the last.

The fertile window depends on how long your menstrual cycle is and the duration of your menstrual period. The typical menstrual cycle is of 28 - 32 days.  But it is normal for women to have cycles ranging from 25-35 days. You can use this time along with other factors like cervical mucus and basal temperature to best pinpoint your most fertile period. This does not mean that you cannot conceive on other days, but this is when you are most fertile or the most likely to conceive.

During the time of ovulation, an egg is available to be fertilized for only about 12-24 hours. But since sperm can live in the body for 3-5 days and then the egg is available for one day, your most fertile time is considered to be about 5-7 days.

Ovulation calculator

Cervical mucus (Fertility Signal)

Once your periods are over,  you will typically have a few "dry" days. Within the first week you may notice your cervical secretions become sticky. As the time of ovulation approaches your cervical mucus will become creamier, changing to clear, slippery secretions that can be stretched between your fingers. Your mucus acts as a slippery highway for any sperm. This is your time of peak fertility.

When checking your mucus look for color, consistency and quantity. This can be noted in your fertility log.

Here are some guidelines:

• Insert one or two fingers in your vagina
• Does your vagina feel dry, moist or very wet?
• Is the cervical mucus creamy, slippery and stretchy?
• Is your cervical mucus clear, white or nonexistent?

During ovulation (when you are most fertile), your cervical mucus should be clear and slippery (can be stretched between two fingers). Many say it looks and feels something like raw egg white.

Some women may feel squeamish about checking their own cervical mucus, but it's really an empowering way to monitor your body's changes and help you get pregnant.

Keep in mind that sexual arousal, the presence of semen, use of lubricants or spermicides, use of an antihistamine (drying) or a decongestant (liquefying),a vaginal infection, or even some fertility drugs can affect your cervical secretions.  So, use this information along with other factors like basal temperature and day of your cycle to best pinpoint your fertility.

Basal body temperature or BBT (Fertility Signal)

Basal body temperature (BBT) is the temperature of your body at rest, when you first wake up in the morning. BBT is lower during the first two weeks of the menstrual cycle, prior to ovulation. The presence of the hormone oestrogen keeps the BBT low. Typically it will range from 36.1 to 36.4 degrees Celsius (97.0 to 97.5 degrees Fahrenheit). Immediately following ovulation, progesterone turns up the heat a bit, and there is typically a rise of at least 0.2 to 0.4 degrees Celsius (0.4 to 0.6 degrees Fahrenheit) until the time of your next menstrual period. After your menstrual period starts, it comes down.

If your BBT remains elevated even past the time that your menstrual period is due, it could be a very early indicator of pregnancy.

This temperature rise will let you know that ovulation has occurred. So as soon as you see it rise (about 97.4 to 98.1 degrees Fahrenheit/36.3 to 36.7 degrees Celsius), its a sign that your fertility period has started. So the best time to have sex for conception is for the next 2 days.

Remember to take your temperature, at the same time everyday for consistency in comparing.  Many take it the first thing in the morning since BBT is the most accurate (least affected by the other factors) when you first wake before you do anything else. Keep a fertility log.

But as we know, the body's temperature can be affected by other factors like illness etc., so do not rely only on this method.  Look at it along with other fertility signs like your cycle, cervical mucus etc.

Position of the cervix (Fertility Signal)

The position of your cervix (the lower portion of the uterus) used along with other fertility signals like BBT etc. can help narrowing down your fertility window even more. During ovulation, the cervix will be soft, open and low (easy to reach). Other times it will be closed, firm and high (difficult to reach).

Here are some guidelines for checking the position of your cervix:

• Wash your hands prior to checking your cervix.
• Check the position of your cervix around the same time each day.
• Many women find it easy to check their cervix while they are sitting on the toilet.
• Gently insert one or two fingers into your vagina. Reaching back you should be able to feel your cervix.
• Does your cervix seem easy to reach (low) or difficult to reach (high)?
• Does your cervix feel soft (like your lips) or firm (like your nose)?
• Does the entrance of your cervix feel slightly open or closed?
• Does your cervix feel dry, moist or very wet?
• Update your fertility log

If you find this very cumbersome, then you could use other fertility signals like BBT and cervical mucus. But of course using this method as well can make your fertility prediction more accurate.

 

Ovulation calculator

 

Ovulation predictor kits

There are also ovulation predictor tests which measure hormone levels in your urine and can be pretty accurate. These can help you in predicting your fertile time more accurately. The kits measure the level of Luteinizing Hormome (LH) in your urine. This hormone surges about 24 - 48 hours before you ovulate. Therefore these kits are known as LH-surge kits. Though not commonly available, they can be found at some of the larger pharmacies in India.

It is recommended that these kits be used in addition to the other methods. Indian women should not rely exclusively on these predictor kits to monitor their fertility.

Keep a fertility log

Keeping a fertility log (on the computer or even on paper) can be an invaluable tool for understanding your fertility cycle.  This way you can watch out for patterns and predict your fertility time better in the future.  You can also share this information with your doctor in working towards pregnancy.

Sample log format:

If you find it cumbersome to determine your cervix position, you could omit this. But noting this might make your fertility pinpointing more accurate.

Secondary fertility signals

There are some other signs that might occur when women ovulate.  These are light spotting, slight pain in one side of the abdomen, breast tenderness, abdominal bloating and an increased sex drive.  You can observe these while tracking your fertility. However, these signs are not consistent.

Some things to note while timing your fertility

If you have an irregular cycle (your periods do not occur in regular intervals and regular duration), then it might be challenging to use fertility signals very accurately for conception and you should talk to your doctor.

Understanding your fertility signals and timing with sex can help you get pregnant faster.  For many it can take the pressure off having daily sex.  But if you have tried to use this fertility awareness method and are getting frustrated and stressed, it defeats the purpose of using this method.  In this case, do not worry and just continue having sex frequently.

Last updated: August 27, 2008