How soon can you take a pregnancy test, and how accurate are they? Fertility specialist Dr Larisa shares her expert advice.
There are early signs of pregnancy that you can look out for, but many women don’t experience all of them (if any at all), so the best way to tell if you’re pregnant is to do a home pregnancy test.
How early can you take a pregnancy test?
If you’ve missed a period, regardless of whether or not you’re using contraception, it’s a good idea to do a pregnancy test to check. If you’re actively trying to conceive and you don’t want to wait until you’ve missed your period, you should wait at least one to two weeks after you had sex as some very sensitive tests may be able to detect a pregnancy at this stage.
How do pregnancy tests work?
Pregnancy tests look for a special hormone in the urine or blood called hCG (human chorionic gonadotropin) that is only there when a woman is pregnant.
hCG is only made in your body after a fertilised egg implants itself in the uterus and this usually happens around 6 days after conception – however, this can vary from woman to woman. The further along your pregnancy you are, the higher the level of hCG in your body.
How soon can you take a pregnancy test?
Home pregnancy tests may claim that they can tell if you’re pregnant on the day you expect your period and it’s possible to tell even a couple of days before your period, but this is not usually the case. It’s not always possible to be that specific about the date of your period, and levels of hCG vary greatly from woman to woman.
Women all have different menstrual cycles and so everyone ovulates at a different time. This will affect when your period is due. You may also have conceived later in your cycle than average, which will affect how much hCG is in your body.
Although you may not want to wait, the best way to be sure is give it at least a week after your period is due.
Pregnancy tests: Early signs you may need to take a pregnancy test
A missed period
One of the first and most reliable signs of pregnancy is a missed period in a woman who has regular periods. However, your period can sometimes be delayed or skipped due to stress, diet, exercise, or certain medical conditions.
Women all have different menstrual cycles and so everyone ovulates at a different time. This will affect when your period is due. You may also have conceived later in your cycle than average, if ovulation has been affected by something, even lifestyle. Although you may not want to wait, the best way to be sure is give it at least a week after your period is due.
Implantation can also produce a feeling similar to menstrual cramps, except you won’t get a period associated with it. This can be an indication you’re pregnant.
Due to the increased production of oestrogen and progesterone, your breasts may feel tender and appear bigger due to increased blood flow. Your nipples might hurt and the veins might look darker under the skin.
You feel unwell
You may get nausea, food aversions, exhaustion and find yourself going to the toilet often to urinate. You know yourself, so pay attention to your body and any unusual physical symptoms that could mean you are pregnant.
How do you do a home pregnancy test?
There are many different types of home pregnancy tests and they cost between £6-12. Most of them work by telling you to urinate onto a small stick.
There are different ways to collect your urine for the test. Depending on the test you choose, you may have to:
- collect your urine in a cup and dip a testing stick into the liquid
- collect your urine in a cup and use an eyedropper to move a small amount of fluid into a special container
- place the testing stick into the area of your expected urine stream so that it will catch your urine midstream
After the recommended waiting time has passed, the tests will display your results either as a change in colour, a line, a symbol, such as plus or minus, or the words ‘pregnant’ or ‘not pregnant’.
If a line or plus symbol appears, you are pregnant. It doesn’t matter how faint the line or plus symbol is, the result is positive.
Most brands will advise you to repeat the test in a few days, no matter what the result.
If your first result is negative, it doesn’t mean you’re not pregnant. There might not be enough hCG in your body yet – take it again in a few days.If your first result is positive, you’re almost definitely pregnant. False positives are very rare, although they do sometimes happen, especially if you are on certain medication.
How accurate are home pregnancy tests?
Home pregnancy tests are very accurate and most claim between 97 per cent and 99 per cent accuracy, but as with any kit there are things that can affect the test result.
Here are some tips for how to improve their accuracy:
- Check the expiry date and make sure you follow the instructions properly.
- The amount of hCG or pregnancy hormone in your urine increases with time and is often different at certain times of day. The earlier after a missed period you take the test, the harder it is to spot the hCG. Also, testing your urine first thing in the morning may boost the accuracy.
- The amount of hCG in urine is different for every woman. Some women will have accurate results on the day of the missed period while others will need to wait longer.
- Some tests are more sensitive than others, and will affect how early you can use them to detect pregnancy.
Dr Larisa Corda is an obstetrician and gynaecologist and one of the UK’s leading fertility specialists
Do you want to share your fertility story? Head over to our Facebook page and let us know.