How accurate are Clearblue Pregnancy Tests?
All Clearblue Pregnancy Tests are more than 99% accurate at detecting pregnancy, when used from the day your period is due.
When can I test with Clearblue Pregnancy Tests?
Clearblue recommend you take a pregnancy test from the day your period is due. However, the level of pregnancy hormone increases rapidly in early pregnancy and most Clearblue Pregnancy Tests can be used up to 4 days before your period is due. If you take a pregnancy test before your period is due and get a ‘Not Pregnant’ result, there is still a chance that you may be pregnant because the level of the pregnancy hormone was not high enough for the pregnancy test to detect. See the Clearblue Pregnancy Test product pages for details of results of clinical testing with early pregnancy.
To work out when your period is due, calculate your usual cycle length by counting the number of days from the first day of your period, until the day before the next one starts. If you have irregular cycles, you should allow for your longest cycle in recent months before testing.
If you have no idea when your period is due we recommend taking a pregnancy test no less than 19 days after the last time you had unprotected sex.
I previously tested ‘Pregnant’ but have tested again and got a ‘Not Pregnant’ result, or my period has started. What does this mean?
Whilst the pregnancy test is over 99% accurate at detecting the pregnancy hormone from the day the period is due, it’s possible to get a pregnant result and find out later that you’re not pregnant (i.e. you may later get a not pregnant result, or your period may start). This may be due to natural loss during the early stages of pregnancy, known as ‘early pregnancy loss’, which sadly is not uncommon, as around 1 in 4 pregnancies end in early pregnancy loss. If you do get unexpected results, ask your doctor for advice.
What is ovulation, when does it occur and why it important?
Whether you are thinking about trying for a baby or trying already, gaining a better understanding about how your body works can be a big help. One in two couples could be trying to conceive on the wrong days of the woman’s cyclei, so we’ve put together some information to help you understand your menstrual cycle and the ovulation process. Ovulation happens when hormone changes trigger your ovaries to release an ovum (egg) – usually 12 to 16 days before your next period starts. You are most fertile on the few days leading up to and including the day of ovulation.
The ova (eggs) are contained in your ovaries. During the first part of each menstrual cycle one of the eggs will be prepared for release from the ovary. As you approach ovulation, your body produces more estrogen. This hormone causes the lining of your uterus to thicken and also creates a sperm friendly environment. The higher estrogen level triggers a sudden rise or ‘surge’ in luteinising hormone (LH) which then triggers the release of the egg from your ovary, this is called ovulation.
Normally, ovulation occurs 24 to 36 hours after the LH surge, and you are at your most fertile on the day of the LH surge and the day after.
The egg survives for up to 24 hours after ovulation which is when it can be fertilised. If fertilisation does not occur, the levels of the fertility hormones decline and the next cycle starts with the shedding of the thickened uterus lining (period).
Although the egg only survives for up to 24 hours, sperm can survive for up to five days. That is why you can still conceive even if you have sex 4 -5 days before the egg is released.
i Johnson SR, Foster L and Ellis J. Human Reproduction (2011) 26: i236
What are the chances of getting pregnant during the fertile days?
The chances of getting pregnant will vary cycle to cycle and woman to woman and will be dependent on many variables such as the woman’s age, her partner’s age, their general state of health and lifestyle. In a studyiii, the chances of getting pregnant on each of the days during the fertility window were reported and are shown in the graph below:-
iii Wilcox AJ., et al. NEJM (1995) 333: 1517
How can I find out when I’m most fertile?
There are a number of ways that you can find out when you are most fertile, one of the most simple and accurate is by using home ovulation tests such as Clearblue Ovulation Tests and the Clearblue Fertility Monitor.
Clearblue Ovulation Test or Clearblue Digital Ovulation Test help you pinpoint the 2 most fertile days to conceive naturally, by detecting your LH surge.
Clearblue Digital Ovulation Test with Dual Hormone Indicator is the only ovulation test that typically identifies 4 fertile days…2x any other ovulation test. It tracks the changing levels of both LH and estrogen and its smart algorithm adapts to your personal cycle.
Clearblue Fertility Monitor is proven to almost double the chances of conceivingii by identifying typically 6 fertile days. It not only detects the LH surge and pinpoints your 2 peak fertility days, but can also identify the additional days of high fertility leading up to ovulation, by detecting the rise in estrogen. It also stores your cycle information and adapts its testing regime to your personal cycle.
ii In the first 2 cycles of use. Robinson JE., et al. Fertility and Sterility (2007) 87: 329-334
I've used Clearblue Ovulation Tests for several months and haven't got pregnant. Can I be sure of getting pregnant?
It can take normal, healthy women many months to conceive. There are many reasons why you may not get pregnant, even if you've made love at your most fertile time. So keep trying. If after several months of trying you've had no success, it’s advisable to go to see your doctor to find out more about your next steps.
In the UK, your doctor will usually expect you to have been trying to get pregnant for a year if you are under 35 yrs old or for 6 months if you are 35-40 years old, before he will consider further investigation. If you are over 40 years old then you should ask for advice immediately.
You may also want to learn more about the Clearblue Fertility Monitor. In a study, the Clearblue Fertility Monitor almost doubled the chances of conceiving over the first two cycles of useii. Click here to find out more about the Clearblue Fertility Monitor.