Early pregnancy testing

Dr Joanna Pike

Reviewed by Dr Joanna Pike on Feb 21, 2020

World's No. 1 selling brand*

*The World's No: 1 selling brand in home pregnancy & fertility tests.
Based on international sales compiled using independent market research data (data on file).

When can I take a pregnancy test?

If you think you might be pregnant, you want to know right away. But it’s important to understand what’s happening in your body so you know how soon you can test.

Early Pregnancy Testing

When did your last period start?
E.g., 28/10/2021
Your usual cycle length:
If you took an ovulation test add the date of your positive result here (optional)
E.g., 28/10/2021
Calculate when I can test

First day you can test

Digital Ultra Early Pregnancy Test
Clear results in words 6 days early

Your personal cycle information

Start of your last period
Positive ovulation test date
Your usual cycle length:
Results are based on the information you have provided.
Change my information

All you need to know about testing early for pregnancy.

After the egg is fertilised, it travels to the uterus (womb) and implants itself in the uterine wall. At this stage tiny amounts of the pregnancy hormone, hCG, start to appear in your urine. It is this hormone that all home pregnancy tests detect and some tests are so sensitive that they can be used up to 6 days before your missed period (which is 5 days before your expected period).

So, for example, if you expect your period on 15th of the month, you can test as early as the 10th. Use our helpful ‘when to test’ calculator to find out when you can test with Clearblue Digital Ultra Early Pregnancy Test - no test can tell you sooner. 

No matter when you test, you can be confident in the accuracy of a 'Pregnant' result with any Clearblue Pregnancy Test.

But if you are testing early, you should be aware that even if your result is not pregnant, you may still be pregnant. This is because levels of hCG vary from woman to woman and there may not yet be enough hormone for the test to give a positive result. HCG levels rise rapidly in early pregnancy, as shown in the graph below, meaning that if you test again on the day of your expected period, your result (whether positive or negative) will be over 99% accurate.

The day of your expected period is the day your period is due to start. If you still haven’t got your period the next day, this is the day of your missed period. So if you see instructions telling you to take the test four days before your expected period, this is the same as five days before your missed period.

Rise of pregnancy hormone
(hCG) in early pregnancy

Relative hCG
hCG can start to appear in urine around this time
First day you can test with Digital Ultra Early Pregnancy Test
Days before missed period

So if you are thinking of testing before your missed period, why not try Clearblue Digital Ultra Early, which gives unmistakably clear results in words. See chart below for results of lab testing with early pregnancy samples:


First day you can test  
Day vs missed period -6 -5 -4 -3 -2 -1 0
Day vs expected period -5 -4 -3 -2 -1 0 +1
% of Pregnancies detected 78% 96% > 99% > 99% > 99% > 99% > 99%
  1. Missed period’ refers to the day after the day you expect your period. In lab testing 78% of pregnant results were detected