Ovulation Tests

Everything you need to know about ovulation tests

How can ovulation tests help me get pregnant?

There are only a few days in each menstrual cycle when you can get pregnant, which is why it’s important to know which are your most fertile days. An ovulation test can accurately tell you when you are most likely to conceive if you have intercourse and can help you get pregnant faster. Ovulation tests work by identifying the rise in hormones that surge just before you release an egg, so you know when you should have sex to get pregnant. Measuring basal body temperature will only tell you you’ve ovulated after your ovary has released an egg, and since eggs only live for 12-24 hours, it may be too late to start trying that month. That is why Clearblue offers a wide range of ovulation tests and fertility monitoring products that detect the rise in the luteinising hormone (LH) or both LH and estrogen to help you better understand your body's ovulation cycle and identify your fertile days to maximise your chances of getting pregnant naturally.


How do ovulation tests work?

In each cycle an egg is released from one of your ovaries: this is called ovulation. Estrogen levels rise in your body in the days before the surge of the luteinising hormone (LH). Estrogen helps your body prepare for ovulation by thickening the womb lining and is also responsible for the appearance of sperm-friendly cervical mucus. The rise in estrogen indicates that you are entering your high fertility window, which can usually be four or more days. Your peak fertile days coincide with the LH surge, which happens around 24-36 hours before you release an egg.

Since sperm can survive for five days, knowing your high fertility and peak fertility days by measuring your hormones can help you plan the best time for intercourse and maximise your chances of getting pregnant. This is where ovulation tests come in to help, as these detect the rise of these hormones in your urine. Since each woman is unique, and menstrual cycles not only vary between women, they can also vary from cycle to cycle in you, ovulation tests take out the guess work for identifying your most fertile time to get pregnant.

Before testing

The Clearblue Digital Ovulation Test detects this rise LH, so you can identify your 2 best days to get pregnant.

When can I do an ovulation test?

When to start testing will depend on the length of your cycle and which Clearblue test you are using. Please check the instructions before you start testing.

You can also use our when to start ovulation testing tool to find the right day to start testing for you. You just need to input your average cycle length, the day your last period started and which ovulation test you’re using.


How to use an ovulation test?

How you take the test will depend on the brand and the test you are using. Once you find out which is the right day to start testing, take your ovulation test using the first urine of the day, either in a stream or by dipping it in a cup and wait for the results. Test daily until you see your peak fertility days. Using a home ovulation test means you can check to see the days you are at your most fertile easily, and conveniently.

Do note that since each test is different, it’s important to read and follow the instructions carefully so that you do the test correctly and get the most accurate results.


How to read an ovulation test?

How you read an ovulation test will depend on the test you are using, as each test will have its own way of presenting your fertility results. The Digital Ovulation Test gives you your results with a smiley face. When your ovulation test tells you you’re at high or peak fertility, this is the best time to have intercourse if you’re trying for a baby.

There are other methods to identify my most fertile days. Which one is right for me?

There are only a few days each cycle when you can get pregnant, so knowing these can help maximise the chances of conception, but what methods are out there?

You can see more about how to predict your fertile days in our video below.

The Calendar Method. This is a simple method which requires you to track your cycles so you can try and predict when you ovulate. If you have a regular cycle ovulation normally happens between 12 and 16 days before your next period starts. To predict ovulation you will need to track your cycles for at least a couple of months. The problem with this method is that the day you ovulate can still vary between cycles and in studies the calendar method has been found to predict the correct fertile days in only one third of cycles1

Apps. There are several apps available, often free, and many use the simple calendar method, requiring you to enter information about your cycle length and periods to predict your fertile days. Some also use data from measuring your Basal Body Temperature or changes in your cervical mucus. 

Measuring your Basal Body Temperature. This is a popular method where you take your body temperature each morning before you get out of bed. You should see a rise in 0.4-1.0°C in your body temperature after ovulation. This method is not ideal because once you have seen this rise you have already ovulated. As the egg only survives 12-24 hours after ovulation it’s too late in this cycle to optimise your chances of getting pregnant. It takes several cycles to build up a picture of your fertility window, and body temperature can be affected by other factors, such as travel, sleep changes, and alcohol. This method has been shown to be less than 70% successful2

Using an ovulation test. The most effective way to determine when you are at your most fertile is to track your hormones, which can be done using an ovulation test. Some ovulation tests detect the LH surge to pinpoint your 2 most fertile days but others detect both estrogen and LH providing a wider fertile window. Clearblue tests are at least 99% at detecting the LH surge and maximise your chances of getting pregnant.

Over 30 years of Clearblue firsts

Clearblue has been a pioneer in pregnancy testing for over 30 years, and we have continued to innovate and create products to help women like you on their pregnancy journey. We’re proud of our long history, and we wanted to share some of our firsts from our Clearblue history.

  • 1985

    We launch the Clearblue Pregnancy Test System, which is the world’s first rapid pregnancy test that gave accurate results in just 30 minutes.

  • 1989

    Clearblue develops the world’s first one-step Ovulation Test.

  • 1999

    We launch the world’s first dual-hormone Fertility Monitor to indicate all the fertile days of the cycle.

  • 2004

    Ovulation results become clearer with our first Digital Ovulation Test, which gave you clear results with a simple smiley face.

  • 2013

    Clearblue launches the world’s first ovulation test with a dual-hormone indicator.

  • 2014

    Clearblue launches the world’s first Advanced Pregnancy Fertility Monitor with pregnancy testing.

  • 2017

    Clearblue launches the first ovulation test with the benefit of connecting to your phone via Bluetooth®

  1. Ellis JE., et al. Human Reproduction (2011) 26: i76
  2. Brezina PR., et al. Fertil & Steril (2011); 95(6): 1867-78

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