Your Guide to Cervical Mucus – What It Is, Why It Occurs and the Role It Plays

Cervical mucus is what we generally refer to as vaginal discharge. If you know how to read its signs, this mucus can give you valuable information about your body – such as telling you that you're in your fertile window, or it may point to a possible infection.

Find out how to read your body's signals. In this article, we explain how cervical mucus changes throughout the menstrual cycle and across your reproductive life, what normal vaginal discharge looks like at each stage, and how to recognise when something isn't quite right.

Cervical mucus – what it is and what it does

Cervical mucus is that gel-like, transparent fluid that you most likely know as vaginal discharge.

The cervix is the connection between your vagina and your womb, and it contains a large number of glands. These glands produce mucus in response to hormonal changes in the body. Over the course of a menstrual cycle, the hormones in and around the cervix stimulate these glands to produce cervical mucus in varying amounts and consistencies.

The central role of this secretion is closely linked to fertility and conception, but it serves many other functions too. Cervical mucus is released into the vaginal canal and:

• keeps the vagina moist and clears it of germs.
• provides a habitat for the “good” bacteria in the vagina, thereby maintaining a healthy flora.
• prevents infection, as it acts as a kind of barrier between the vagina and the outside world.
• filters and transports semen during the fertile phase, helping sperm to fertilise the egg and reach the womb.
• prevents semen and other bacteria or substances from reaching the cervix when it thickens (for example, in response to contraceptives).

Cervical mucus changes naturally throughout the menstrual cycle, but also in response to inflammation and infection. That's why it's important to know which changes in colour and consistency are normal and which aren't – so you can tell your body's natural rhythm apart from a possible medical condition.

 Causes of changes in cervical mucus

Since it's hormones that control mucus production in the glands of the cervix, any hormonal change is the main cause of changes in vaginal discharge.

Throughout a woman's reproductive life, a great many hormonal fluctuations take place in the body – and with them, changes in mucus. This is perfectly normal, as long as no unusual colours or odours appear.

Below you'll find out the main reasons why cervical mucus changes over the course of the menstrual cycle, and what other changes you might notice throughout your life.

 The menstrual cycle

This is the main cause of the monthly changes in vaginal discharge. The consistency and shade of cervical mucus can change at each stage in line with hormonal fluctuations: from no mucus at all, to thin, watery discharge, to creamy or egg-white-like mucus.

This is precisely why it's such a good indicator of which phase of the menstrual cycle you're in. Many women trying to conceive track these changes to work out when they're ovulating and when they're at their most fertile.

We've covered more about all these hormonal changes and the phases of the menstrual cycle in our article on menstruation – there you'll find everything you need to know about periods.

Pregnancy

Immediately after conception, cervical mucus thickens and may change colour from transparent to whitish or yellowish.

In the first trimester, it's normal to notice yellowish discharge during pregnancy. Towards the end, it may change into a pinkish discharge – a sign that the due date is approaching. Pink streaks in cervical mucus during pregnancy can signal the onset of labour.

Infections

If you notice an unusual change in your cervical mucus, there's a strong chance an infection is behind it.

If the discharge turns yellow or greenish, contains blood, or has an unpleasant smell, the cause could be a bacterial infection, a fungal infection, or even a sexually transmitted disease. We've put together everything you should know about sexually transmitted diseases in another blog article.

Book a gynaecological appointment as soon as possible to determine the exact cause and treat the condition early, so that complications can be avoided.

Contraceptive methods

Hormonal contraceptives act at a hormonal level and cause fluctuations. In doing so, they automatically influence the way the cervical glands produce mucus. Read more HERE about contraceptive methods and how they work.

Generally speaking, contraceptive methods such as the pill alter cervical mucus and thicken it, making it harder for sperm to reach the womb and therefore harder for fertilisation to occur.

Other factors

The menstrual cycle, infections, pregnancy and contraception aren't the only causes of changes in cervical mucus. It can also change in response to other internal and external factors, including:

• Certain medications: These can affect mucus production in the cervical glands (antihistamines, for example, can dry out vaginal discharge).
• Intimate hygiene products and douches: These can cause irritation of the vaginal lining or dryness and trigger infections, which in turn alters vaginal discharge.
• Sexual intercourse: The vagina's natural lubrication can change the appearance of mucus; in addition, injuries resulting from intercourse can alter vaginal discharge.
• Breastfeeding: This affects the signs of fertility, including body temperature and cervical mucus.
• Lubricant used during a gynaecological examination: This can temporarily change the appearance of cervical mucus.

How does cervical mucus change over the course of the menstrual cycle?

It's normal for vaginal discharge to change at every stage of the menstrual cycle, because hormone levels also rise and fall. Below we explain how vaginal mucus naturally changes over the course of a month.

Cervical mucus during your period

During your period you probably won't notice the mucus, as it's masked by menstrual blood. If you track and record changes in your vaginal discharge, there's no need to do so during your period. Instead, now is the time to observe your menstrual blood: how long the bleeding lasts, how heavy it is and what other symptoms you have.

Cervical mucus after your period

You may have noticed brownish discharge after your period. This is normal and usually doesn't contain cervical mucus. The days immediately after your period ends are the “driest”: the gel-like discharge may be completely absent, or dry and sticky.

 Cervical mucus before ovulation

Before your ovaries release an egg, the cervical glands begin producing mucus. During this time the discharge is watery or sticky, and the colour can range from cloudy white to yellowish.

 Cervical mucus just before ovulation

If you notice that your cervical mucus takes on the form of a white, creamy discharge, this is a sign that ovulation is very close. Shortly before ovulation the body produces more oestrogen, and cervical secretions can become more slippery or watery.

Cervical mucus during ovulation

Cervical mucus at the time of ovulation has the consistency of egg white. It's transparent, stretchy and very wet. The consistency and pH of the discharge are optimal at this time to support fertilisation and the transport of sperm to the womb. 

Cervical mucus after ovulation

After ovulation, mucus production decreases and the discharge thickens. It becomes stickier, cloudier, or disappears entirely for a few days. The discharge stays dry until bleeding begins, and the cycle starts all over again.

What should cervical mucus look like

Depending on the phase of your cycle and your level of fertility, mucus should be wetter or drier, more watery or stickier, with clear or cloudy shades of transparent, white or yellowish. All of these types of mucus are normal in their respective phases:

• Dry or sticky
• White and creamy in consistency
• Wet and watery
• Like egg white, present in abundance
• Transparent and gel-like
• Absent
• Yellowish in colour (particularly during pregnancy)
• Not discernible (during your period, when it's masked by menstrual blood)

As you can see, cervical mucus goes through a great many changes in consistency and colour, all of which are perfectly normal. The only way to recognise that something isn't right is to know your body's natural changes.

How to check your cervical mucus

Checking your cervical mucus is NOT compulsory. That said, it's always helpful to know your own body – all the more so if you're hoping to have a baby. Vaginal discharge can be a good indicator of your fertile phase and help you pinpoint those days when pregnancy is most likely.

When checking your vaginal discharge, you should take into account both its visual characteristics (appearance, colour) and its consistency and smell.  So if you want to track how your cervical mucus changes, you'll need to examine it carefully.

You can assess it visually by looking at your underwear, or at the toilet paper after you've urinated. Alternatively, you can check it by inserting a finger into the vagina to collect some discharge. The latter may seem a little uncomfortable at first, but it becomes easy once you've got used to it and developed a routine. Follow these steps for an accurate assessment:

• The first thing you should always do: wash your hands thoroughly and dry them.
• Choose a comfortable position – either standing, or over the toilet with one leg raised.
• Carefully insert a finger into the vagina to collect some discharge.
• Depending on how abundant the fluid is, you may be able to feel it without inserting your finger deeply – or you may need to reach as close to the cervix as possible.
• Remove your finger and examine the discharge. First note its appearance and colour, then bring your thumb and the mucus-covered finger together and apart several times to assess the consistency.
• Wash your hands afterwards.
• If you're tracking your fertility using cervical secretions, now is the moment to make a note of your observations.

How do you know when something's wrong with your cervical mucus?

Any unusual change in mucus can be a sign that something isn't right. This could be a change that's unusual in general (for example, a greenish colour or an unpleasant smell) or one that's unusual for you (for example, very abundant discharge on days when there normally wasn't any).

The clearest signs that cervical mucus isn't normal are usually:

• Grey, yellow or green discharge
• Discharge accompanied by itching, stinging or burning
• Discharge with a crumbly, cottage-cheese-like consistency
• Mucus containing traces of blood (outside your period)
• An unpleasant smell
• Redness, swelling or pain in the intimate area

As soon as you notice a change like this, you should see your gynaecologist to get the situation assessed and receive any necessary treatment.

Cervical mucus and fertility

As we explained above, the hormonal changes during the menstrual cycle have a direct effect on the production and appearance of cervical mucus. During the ovulation phase, both your basal temperature and the secretions from the glands at the cervix increase. It's therefore a good indicator of your level of fertility throughout the month:

• No mucus, or mucus that isn't visible and is dry: the least fertile phase.
• A sensation of wetness, but the mucus still isn't visible: low fertility.
• Thick, white or yellowish discharge with a creamy, sticky consistency, but not stretchy enough to be pulled apart: moderate fertility.
• Transparent, abundant mucus, slippery and fine, which is elastic and stretches like egg white: the most fertile phase.

Together with basal temperature and the calendar method, observing your mucus can help you work out your fertile window (when you reach your peak fertility) and identify when pregnancy is most likely. If you'd like to learn more about how the calendar method works and how reliable it is, read our article HERE.

If you DON'T want to get pregnant, you should avoid unprotected sex and not rely on the low fertility estimated from observing your mucus. This isn't an effective method of contraception and has a very high failure rate. There are far more effective contraceptive methods for protecting against an unwanted pregnancy – both hormonal (such as the pill) and barrier methods (such as the condom).

 Cervical mucus and pregnancy

Pregnancy is another important factor that affects the production of cervical secretions and alters their appearance. After conception, it's normal for cervical mucus to become thicker. It may also become more abundant at the same time and take on a yellowish colour.

You may notice that the discharge becomes thicker, transparent and rubbery even before a pregnancy test comes back positive. It may contain small amounts of blood 6–12 days after conception. This is called implantation bleeding and is normal, as it's a sign that the fertilised egg has implanted in the lining of the womb.

In the latter part of pregnancy, you may notice that the discharge contains pink traces or streaks.  This can be one of the signs that labour has begun.

 When to see a doctor about changes in cervical mucus

As soon as you notice unusual changes in your cervical mucus, you should discuss them with your doctor.

Outside of pregnancy, an unpleasant smell and greenish or grey colours can indicate an infection that needs medical treatment. During pregnancy, unusual or bloody discharge can point to certain conditions; here too, medical care is required. Cervical mucus is a very good indicator of your reproductive health, so it's always a good idea to tell your doctor about any change.

In addition, if you notice that you never have fertile cervical mucus (that is, transparent, gel-like discharge resembling egg white), this may indicate a hormonal imbalance and could affect your ability to conceive. Raise this point with your gynaecologist too, in order to prevent or treat any potential fertility problems.