This is a question that plagues many women. It can be a frustrating and scary time, waiting to find out if you’ve actually conceived. This is especially true for women who have been trying to get pregnant for a while or have had many negatives come up before.

The biggest problem is that many women take a pregnancy test far too early. It’s essential to wait until after your menstrual period is late so that your uterus can build up enough hCG to be detected by a test. Most home pregnancy tests have a sensitivity of 25mlU to the hormone.

Let’s start at the beginning. Firstly, you must be in your fertile period when you have sexual intercourse in order to conceive. This period can vary significantly in terms of when it happens, especially if your cycle isn’t regular. It is usually the five days before ovulation and the day of ovulation.

When is a woman actually pregnant?

Conception or fertilization of the embryo doesn’t always lead to a pregnancy. This is because the egg still has to reach the uterus and implant itself into the endometrium. This process can take anywhere from 7 to 15 days before nidation (implantation) occurs.

So how many days after nidation will a home pregnancy test show as positive?

Essentially, you have to wait until enough hCG has built up in your body before the test will show up as positive, and your body only starts producing hCG after nidation. Many women will try a test before they’ve even waited a week after sexual intercourse. This means that there may be a fertilized embryo that will implant itself, but no hormone to show a positive result.

This is often what happens when you get a false negative.

How to avoid a false negative

It’s simple, just wait until the appropriate time in your cycle before you take a test.
This is why it’s important to know your cycle as this will help you to pinpoint the right day for testing. If you know when you usually ovulate, you can work out when you are meant to start menstruating – usually 13-15 days later. It is at this point that you should be able to get a positive result if you are pregnant.

If your cycle is irregular, it can be very difficult to work out when you should be taking a pregnancy test. This is because the time between menstruation and ovulation varies in your cycle. However, if you are aware of the symptoms of ovulation, you can predict when your cycle should start and, therefore, when you should take a pregnancy test.

For those who aren’t sure when they ovulate – either your cycle is irregular or you don’t really get any symptoms of ovulation –it’s recommended that you wait 20 to 30 days after sexual intercourse before testing. This way you are highly likely to get a definite result.

IMPORTANT: Anxiety and the inability to wait are the biggest villains when it comes to false results in a home pregnancy test. Don’t let your uncertainty rush you into taking a test too early.

Which pregnancy test is best?

The tests you can buy at your pharmacy are getting increasingly sensitive and these days, give far better and more accurate results more often. However, the best way to find out if you’re pregnant is to go to a doctor and have a blood test done. The laboratory results will be the most accurate.

Basically what the tests are looking for is the presence of the hormone hCG because this is only produced by the body when an embryo is implanted. Levels of the hormone that are above 25mlU are considered to be a definite positive. Anything at 4mlU or under is considered to be a negative. Levels in between are considered indeterminate and will not show up as a definite answer on any pregnancy test.

Recent studies have shown that a small amount of hCG is actually released at the point of fertilization. This would often explain the really low amounts that end up being a positive result further down the line.

When a test comes up as negative, it’s recommended that you wait another 48 hours before trying again. This is to give the hCG time to build up some more in your system – if you are indeed pregnant.

In order to get the best chance of an accurate result on a home pregnancy test, rather try first thing in the morning. Your first urination of the day usually has the highest concentration of hCG in it. You can also look for a more sensitive test as some are designed to register as low as 10mlU.

It is also said that an ovulation test that you can buy from a pharmacy will actually also detect hCG. They are designed to detect LH in urine and this hormone is very similar to hCG.

A false negative after the first day that menstruation is due

There are times when you can get a negative result on a test even after your menstruation is officially late. This can be due to a delay in ovulation, which leads to a delay in your menstruation start date. Therefore, it will take a little bit more time than you initially thought for hCG to build up enough in your body. This is why it can be a good idea to do a second test a couple of days later just to be sure that it wasn’t a false negative the first time round.

To summarize: Taking a pregnancy test too early can lead to a false negative. You have to give your body enough time to build up hCG in order for the tests to read it in your urine or blood. The longer you wait, the more likely you are to get an accurate reading. It may be frustrating, but do wait until your menstrual period is definitely late.

A positive result before your menstrual period is actually late

We’ve all heard of at least one person – a friend, your sister-in-law or a work colleague – who got a true positive result on a home pregnancy test before they were even late on their menstruation. These women are the exception to the rule.

It’s possible that they had an irregular cycle that month and they actually ovulated earlier than usual and were actually late on their menstruation. Alternatively, they just happened to be lucky with the test.
It’s definitely best to wait and not believe that you may be one of the lucky few.

Readers’ questions:

How long after sex should I take a pregnancy test?

Regardless of when you engaged in sexual intercourse, it’s best to wait according to your menstrual cycle. Once your menstruation is late, you have a good chance of getting an accurate result on the test.

I’ve been in a sexually active relationship for a month, when can I take a pregnancy test?

To avoid possible frustration and a false negative, a pregnancy test should only be taken when your body shows the right signs. These include menstrual delay, as well as symptoms like nausea, dizziness and tenderness in the breasts.

I’m not getting a full menstruation, only a bloody discharge. Should I take a pregnancy test?

A brown discharge is not necessarily a sign of gestation. While it can be, it can also be a result of low hormone levels. You can also experience a bloody discharge from embryo nidation, or from medication like the morning after pill.