How Sensitive is Your Pregnancy Test and Why is it Important?

most sensitive pregnancy tests

Not all pregnancy tests are made the same! But which are the most sensitive pregnancy tests that can give you a result as soon as possible?

Before we started trying for a baby I thought a pregnancy test was a pregnancy test – they all did the same thing right?

…Well, sort of!

While they all tell you whether or not you’re pregnant, some can tell you a lot sooner than others and can predict a pregnancy nearly a week earlier than others on the shelf.

As standard with at home pregnancy tests there are two options:

Analog tests – where you look for an extra line or a cross

Digital tests – with a straight up pregnant or not pregnant answer

…but both of those options have various brands and types with different sensitivities. 

At home pregnancy tests work by testing the level of HCG (the pregnancy hormone) in your system. Each brand and type of test has different thresholds so you either need more or less HCG to trigger a positive result.

This is important to know as it means you may get a false negative result on a pregnancy test even if you are pregnant, if your HCG levels aren’t yet high enough to show up on that particular test. 

FUN FACT: The pregnancy hormone – HCG – increases dramatically every two to three days, rising from less than 5mIU/ml to over 100,000mIU/ml in the first three months of pregnancy. 

How to find out the sensitivity of pregnancy tests

Sensitivity for pregnancy tests is measured in mIU (milli-international units per millilitre). So a test that is 12mIU would need 12 milli-international units of HCG per millilitre to trigger a positive result.

Essentially, the lower that number, the more sensitive the test. Less HCG in your system is needed to produce a positive result meaning the test can predict pregnancy sooner. 

Some people can get a positive pregnancy result as early as around 10dpo (days past ovulation) but a lot of advice states to wait until after your missed period before testing. We personally got a faint positive line on one of the following tests at 11dpo which was incredibly exciting! 

You can find out the sensitivity of tests with a flick through their information leaflet inside the box, but it’s not always visible from the outside before buying them. Good old Google can be your best friend for finding out this information if you have a particular brand in mind but here are a few I’ve tried before that I’d recommend…

Which are the most sensitive pregnancy tests on the market?

most sensitive pregnancy tests


First Response Early Result– around 6-7mIU.  We got our first positive result with these and I really rate them! They’re easy to read and they’re the most sensitive I’ve found. 

most sensitive pregnancy tests


Clearblue Ultra Early Digital – around 10mIU.  We confirmed our faint positive with these and again they’re great! Very sensitive and incredibly clear – it’s either a yes, or a no. 

most sensitive pregnancy tests


Easy at Home – around 10mIU. These are a fab and cheap option for early testing as they’re just as sensitive as those fancy Clearblue ones for half the price! You need to dip these instead of weeing on them but they’re a great little test. I got 20 of these with my ovulation tests so I was able to take one of these every day and watch the line get darker as time went on which was very comforting for me.


Regular Supermarket Brands – often around 25mIU. Usually (with exceptions) the bog standard tests you find on the shelves are around 25mIU so will take a bit longer to show a positive result. These wouldn’t be great if you’re planning on testing early before your missed period so definitely keep that in mind. 

(Of course there are other brands on the market too, these are just some I found during our journey.)

It’s also really important to take tests as per the pack instructions and read them within the right timeframe. If you leave them too long before reading your result you may get a false positive. And it’s also important to make sure your line (especially if it’s faint) has some colour to it so it isn’t just an indent mark. 

With the right sensitivity and the right usage you can get an accurate result up to 6 days before your missed period. 

IMPORTANT TIP: Don’t forget the phrasing ‘missed period’ refers to the day your period is officially late, aka the day AFTER your period is due. This one can trip some people up.

Hopefully this post has helped give you a little more information on which are the most sensitive pregnancy tests and why it’s important to know! 

Don’t forget to check out my YouTube channel and Instagram for more honest and easy to digest pregnancy, fertility, hormone and period chats!