Recognising your fertility signs

It is often thought that the day of ovulation is the best day to have sex that will result in pregnancy. This is not strictly true, as the egg survives for only 6 to 24 hours after ovulation before disintegrating. The optimal situation is when the sperm are waiting in the fallopian tube, ready to fertilise the egg as soon as it is released. In order for this to happen, you need at least a couple of days warning that ovulation is imminent. This is possible when you learn to observe your fertile signs.

There are four main indicators that you are in your fertile period, that is the period leading up to and including ovulation. The signs to look out for are:

Changes in cervical mucous (CM)

Changes in cervical position (CP)

A surge of luteinising hormone (LH)

Changes in waking temperature


Changes in Cervical Mucous (CM)

If you’ve never observed your cervical fluid before then you may not be aware of its cyclical nature, even if you have noticed changes in volume and texture over a period of time. Throughout your menstrual cycle, your CM changes in response to the hormonal changes in your body. We have already seen that a sharp increase in oestrogen levels triggers the production of fertile quality CM. Similarly, the other hormonal changes effect the consistency and amount of CM that your body produces. It is important to note that all CM prior to ovulation can be considered fertile to some extent, but that it is the slippery, stretchy type that signals that ovulation is on its way and that is also most conducive to the survival and transportation of sperm.

The way in which you observe your CM is up to you. The most accurate method is to insert your finger into your vagina and collect some CM. However, some women find this too uncomfortable, too messy or simply too much hassle. For the purposes of observing changes in CM, it is absolutely fine to collect it on some toilet paper and have a look at it that way. Make sure you wipe before and after going to the toilet as you will get a better idea of what’s there.

As your menstruation comes to an end, you will probably have a period of dryness or possibly just a small amount of moisture at the vaginal opening. After a few days you may notice a slight increase in CM and that it has a sticky or paste-like consistency. The next type of CM you will have should feel wet and have a creamy texture like hand lotion. As you approach ovulation and your oestrogen levels peak, you should notice CM that looks like egg white (this is usually abbreviated on message boards to EWCM). It is slippery and stretches to more than a quarter of an inch when held between the thumb and forefinger or between two sheets of toilet paper. This is your most fertile CM – whenever you see this, it is time to get down to business. Most women will have between two and four days of EWCM. As soon as you have ovulated, your CM tends to dry up and may remain dry or slightly moist until the end of your cycle. You may also notice that it gets sticky a day or two before your period is due.

Stage of cycle

Cervical mucous


Anecdotal evidence suggests that creamy or lotiony CM during the two week wait may indicate pregnancy. In my experience, there does tend to be more CM than usual during the luteal phase of a pregnant cycle. However, I have also noticed this during some non-pregnant cycles so it is not a sure-fire guarantee by any means. If only there was such a thing….

Changes in cervical position (CP)

The cervix is that lower, narrow portion of the uterus that joins the vagina. As with CM, the CP undergoes changes at specific times during the menstrual cycle, and observation and tracking of these changes can be used to predict ovulation.

I have to say that monitoring of this fertility sign is not for the faint-hearted, and it is something I tried only a couple of times. It is not essential to track your CP, but if your other fertility signs are not conclusive – if you are not producing much CM, not having much of an LH surge or your waking temperatures are not providing an accurate pattern of ovulation – then it is well worth keeping an eye on your CP.

As with taking your temperature and testing for an LH surge, you should check your cervix at the same time every day. Make sure you wash your hands first. Insert one or two fingers into your vagina and push upwards and backwards until you reach the top – this is your cervix. If your cervix is relatively easy to reach, then the position is low; if it is harder to reach, then the position is high. You also need to check whether your cervix feels soft or firm, open or closed and wet or not. These are all relative characteristics that you will only begin to identify when you have checked your cervix on a regular basis over a number of cycles.

Prior to ovulation, your cervix will feel relatively firm (like touching the tip of your nose), dry to the touch, low and closed. As you approach ovulation, your cervix will become increasingly soft and moist and the entrance will start to open and rise in response to the high levels of oestrogen in your body. Around this time the cervix will release fertile quality CM. Once you have ovulated, your cervix will return to the low, hard, closed and dry position.

LH surge

Approximately 12 to 36 hours before you ovulate, your body will experience a surge of luteinising hormone (LH). Changes in the level of LH in your system can be detected in urine and you can test for this using ovulation prediction kits (OPKs) – these are just individual tests, usually sold in packs, hence the name “kit”. OPKs are used in exactly the same way as home pregnancy tests (HPTs) – either you pee directly onto the stick or you can collect your urine in a cup and then dip the stick or the strip into it.

The main difference between HPTs and OPKs is in how you read them. With HPTs, a second line, however faint, is a positive result. In order to get a positive result on an OPK, the test line has to be as dark as the control line. In fact, your LH levels may be high enough throughout your cycle to show a second line on an OPK at any time. It is only when this line becomes as dark as the control line that you have had your LH surge.

Unlike with HPTs, it is better to use OPKs in the afternoon or evening. This is because your LH surge usually begins in the morning, so it is more likely that you will catch it if you test later in the day. I usually test when I come in from work at about 6pm.

It can be difficult to read the results on an OPK – sometimes the test line looks almost as dark as the control line, and if it is considerably darker than the previous day, then there is a tendency to assume it is positive. Most likely what has happened in this case, is that you have caught the beginning or the end of the surge, and if you test again in a couple of hours (or had tested a couple of hours previously) then the test would be positive. It may take you a couple of cycles to be able to read your OPKs with confidence.

When you should start testing for your LH surge depends on the usual length of your cycles. If you have been monitoring your cycles for a while then you may have some idea when you ovulate. If you have no idea then it is best to take the shortest cycle you have had in the last six months and use that as the basis for when you will start testing, to make sure you don’t miss the surge on another short cycle. The chart below will give you an idea of what day or your cycle you should start testing.

Cycle length











Start testing











Cycle length











Start testing











If your OPK is positive most or all of the time then it is possible that you have polycystic ovary syndrome (PCOS). PCOS is an endocrine disorder which results in constantly high levels of LH in the system.

Checking for an LH surge with OPKs is probably the simplest method of predicting ovulation, and it is the one that most newcomers seem to prefer. However, it is possible (although rare) to have an LH surge and still not ovulate, so you if you have any doubts you should cross-check your OPK results with your other fertility signs and use a temperature chart to make sure ovulation has taken place.

Other methods of ovulation prediction

As well as OPKs, there are other devices available that can tell you that your body is gearing up to ovulate. They are usually referred to as fertility monitors but different types use different methods of detecting impending ovulation. They range in price from about €20 to several hundred euro so tend to be bought as an investment by those who have tried other methods unsuccessfully or those who are planning more than one baby. It is important to remember that, while these monitors can tell you when you are about to ovulate, the readings do not guarantee that you will actually ovulate. If you are concerned that you may not be ovulating, then you should chart your temperatures also.

Urine monitor

Urine monitors, usually called fertility monitors, are hand-held electronic devices that measure the levels of oestrogen and LH in your system, and give you a reading of low, high or peak fertility. These monitors require a monthly purchase of test sticks or discs so they can be a costly investment. At a specified time each day, you collect your urine in a cup and dip the stick in the cup or drop your urine onto a test disc. The monitor will then return a reading based on your hormone levels. Urine fertility monitors are available from and cost about €140. The test sticks cost about €30 for 20 sticks.

Electrolyte monitor

These monitors measure the electrolytes in saliva and/or cervical mucous by means of a probe attached to an electronic device, and can predict ovulation from five to seven days in advance. Some monitors will store your readings in their memory so you don’t have to make a note of them every day – some even have the facility to upload the readings to your computer. These cost several hundred euro but do not need any additional purchase apart from a battery. I can’t recommend any sites that sell them, although I have seen them on eBay.

Salivary ferning test

Saliva monitors, also known as saliva microscopes or ovulation monitors, show a ferning pattern when you are approaching ovulation. First thing every morning, you take a bit of saliva on the tip of your finger and smear it onto the lens of the microscope. After about five minutes, you can look at the monitor and determine whether or not you see a ferning pattern. These monitors are available from for US$25.

Changes in waking temperature

When you ovulate, your temperature rises. This is due to the large amounts of progesterone that the corpus luteum produces. A woman’s preovulatory waking temperature ranges from approximately 36 to 36.5 degrees Celsius, and this rises to about 36.5 to 37 degrees within a day or so after ovulation. These temperatures stay high until the corpus luteum starts to break down and stops producing progesterone – this is usually the day before you will get your period, although it can happen on the same day or a couple of days later. If you are pregnant then your temperatures will stay elevated through the time of your expected period and beyond, as the HCG produced by your body will signal the corpus luteum to keep producing progesterone.

It is essential to take you waking temperature at the same time every morning as your temperature will be different at different times of the morning. You will also need a basal body thermometer or one that is calibrated to two decimal places, as even small changes in temperature can be significant.

When reading temperature charts, it is important to look at the pattern of temperatures, as opposed to the individual highs and lows. One temperature in isolation will not tell you anything as many things, such as alcohol consumption and illness, can affect your waking temperature. So don’t worry if one temperature is higher or lower than you expected, the chart will probably even out over the next few days.

Charting your waking (or basal body) temperatures will give you a very accurate picture of when you ovulate. However, it is something that needs to be done over a number of cycles as one cycle in isolation will only tell you when you have already ovulated. If you look at your temperature charts over a period of time, then you will be able to pinpoint your usual day of ovulation (to within a couple of days – you may ovulate the day of the temperature rise, the day after or the day after that) and use that information to predict ovulation in your next cycle.

On an individual cycle basis, your temperature chart is a useful tool for corroborating your other fertility signs, and is the only sure-fire way of knowing that you have actually ovulated. All the other signs signal that you are about to ovulate but cannot guarantee that this will actually happen. Once you see a sustained temperature rise (over three days or more), you can be sure that the follicle has released an egg, has become the corpus luteum and has started producing progesterone.

If your cycles are irregular then your temperature charts may not be useful for predicting ovulation. However, they will tell you when you have ovulated so you will know what phase of your cycle you are in. If you know you have made it into the luteal phase then at least you can relax a bit (or as much as is possible in the two week wait!).

Another less reliable indication is a pain in either or both sides of your lower abdomen around the expected time of ovulation. This pain is called Mittelschmerz (German for “middle pain”) and can last anywhere from a few minutes to several hours. There are several possible causes for this – the swelling of the follicles, the egg bursting out of the ovary, the release of blood or fluid from the ruptured follicle – and it cannot be used to determine the time of ovulation, as it can occur before, during or after ovulation. It is, however, a useful secondary fertility sign that can be used to cross-check the primary fertility indicators.

What if your fertility signs disagree?

If you are keeping track of more than one fertility sign, then it is important to remember that none of them can pinpoint the exact time of ovulation and are accurate to within +/- 2 days. So you may have a positive OPK and your temperature may not rise for another three days – this means that you could have ovulated the day after the positive OPK or the day after that. Some people will ovulate the same day as the positive OPK, some two days later. Some people will have fertile cervical mucous the day of and the day after ovulation, some only up until a day or two before. Similarly, CP and waking temperature will vary amongst women.

If your fertility signs vary to the extent that you cannot match them at all, then the most reliable one to use is your temperature chart. Your temperature will only show a sustained shift once you have ovulated. If you are concerned that your CP, your CM or your LH surge are completely at odds with your temperature chart, then you should see your medical practitioner who can test your hormone levels on day three of your cycle, and again at seven days past ovulation (7dpo) to see if there are any imbalances that may be affecting your cycle.

Other articles:

Dealing with infertility: advice for family and friends

The Baby Battle

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