Article contents

Key points

  • The test detects hCG, a hormone made after the fertilised egg implants in the uterus.
  • It becomes reliable from the first day of a missed period; before that, a negative proves nothing.
  • First-morning urine, which is more concentrated, helps when testing early.
  • A blood test measures the exact beta-hCG level and you don't need to fast for it.
  • Positive test plus pain on one side of the tummy or bleeding: see a doctor the same day.

The stick is sitting on the edge of the basin, and those two or three minutes feel like an hour. A pregnancy test is a simple thing to do, but its result depends a great deal on when you take it and how you read it. Taken too early, it can stay negative even though you are pregnant.

Here is how to choose the right day, when a blood test is the better option, how to interpret a faint line, and where to find a test in Morocco.

How does a pregnancy test work?

All tests look for the same hormone: hCG (human chorionic gonadotrophin). It is only made once the fertilised egg has implanted in the wall of the uterus, from about six days after fertilisation, according to the NHS. It then appears in the blood and then in the urine, at the earliest around ten days after conception.

In early pregnancy, its level climbs very quickly, roughly doubling every two to three days. That is why a few days' wait makes all the difference. A test that is negative on the morning of day 25 of your cycle can be clearly positive a week later.

The first physical signs, on the other hand, are not enough to tell you either way: we go through them in our article on early pregnancy symptoms.

When should you take a pregnancy test?

A urine test is reliable from the first day of a missed period. That is the benchmark used by the UK's NHS and by the Mayo Clinic.

Your situation When to test
Regular cycle From the first day of your missed period
Irregular cycle or unknown period date At least 21 days after unprotected sex
Early test (higher sensitivity) Possible a few days before your period, but a negative proves nothing
Blood test (beta-hCG) About 14 days after sex, according to Santé.fr

Recommendations vary slightly from country to country. France's Santé.fr portal advises waiting 21 days after sex for a urine test, while the NHS puts the first day of a missed period first. The two markers often fall within a few days of each other. If you are unsure of your dates, our article on ovulation and fertile days will help you work them out.

Morning or evening: what time of day?

For an early test, morning is still the best choice. Overnight urine is more concentrated and hCG is easier to detect in it: that is what the Mayo Clinic, MedlinePlus and Santé.fr recommend.

The NHS is more relaxed and says a test can be done at any time of day. In practice, both views fit together. If your period is a week late, the hormone level is usually high enough for an afternoon test to work. If you are testing on the first day of a missed period, or before, use your morning urine and avoid drinking a lot just beforehand.

Urine test or blood test: which should you choose?

A urine test is enough in the vast majority of cases. A blood test gives you one extra piece of information: the precise hormone level.

Urine test Blood test (beta-hCG)
Where At the pharmacy, no prescription needed At a medical testing laboratory
Answer Yes or no, in a few minutes A measured level, often in about a day
From when First day of a missed period A little earlier than a urine test
Preparation Follow the instructions None, no need to fast
Particular advantage Simple, discreet, done at home Tracks how the level changes if your doctor asks for it

Your doctor may prescribe a blood test when the urine result is unclear, if you have bleeding or pain, or after fertility treatment. Two tests a few days apart then show whether the level is rising normally.

How do you read the result correctly?

  1. Check the expiry date and the state of the packaging before opening the test.
  2. Respect the reading time given in the instructions, often two minutes or more. Don't look too early, and don't trust a result you re-read hours later.
  3. Check the control line: if it doesn't appear, the test hasn't worked and you need to do another.
  4. A faint line in the result window usually means the hormone level is still low, which is typical of an early test. Repeat the test two to three days later with your morning urine: the line should be clearer.
  5. Digital tests display a word rather than a line, which avoids any hesitation over reading it.

False negative, false positive: why does a test get it wrong?

A positive result is almost always right. A negative is less reliable, for well-known reasons.

Causes of a false negative:

  • testing too early, before your period is late;
  • reading the result before the stated time is up;
  • urine that is too dilute, at the end of the day or after drinking a lot;
  • according to Santé.fr, certain medicines acting on the nervous system, blood in the urine or a urinary infection;
  • a container washed with washing-up liquid and not rinsed properly, if you collect your urine in a glass.

Causes of a false positive, rarer according to the Mayo Clinic:

  • a pregnancy that stops very early, just after implantation;
  • fertility treatment containing hCG;
  • certain ovarian conditions, or the menopause.

The pill and antibiotics do not affect the test. As for "home-made" methods (salt, sugar, bleach, vinegar), they are not reliable at all.

Where can you buy a pregnancy test in Morocco, and how much does it cost?

Urine tests are sold in pharmacies, without a prescription. In the evening or at the weekend, a duty pharmacy (pharmacie de garde) can help you out. The pharmacist can also explain the difference between the models: simple strip, midstream test, early test or digital test.

Prices vary by brand, type of test and pharmacy: there is no single price. Price doesn't make a test more reliable: according to the NHS, a test is accurate as long as you follow its instructions correctly. What matters most is taking it at the right time.

Blood tests are done at a medical testing laboratory. With a prescription, it may be covered depending on your insurance (AMO, Morocco's compulsory health insurance, or a top-up policy): check with the laboratory and your insurer before the test.

Positive or negative test: what next?

The test is positive. Make an appointment with a gynaecologist, a doctor or a midwife, in a private practice or at a health centre. UNICEF recommends at least one antenatal visit within the first 12 weeks, as early as possible. The first examination and the first scan check that the pregnancy is developing properly in the uterus and allow it to be dated. To find your way around the weeks, see how to work out how far along you are. And if you are wondering who to tell and when, our article on announcing your pregnancy can help.

As for equipment, there is no hurry. The first useful purchase will come when your bump grows: a pregnancy pillow, which you can use again afterwards for breastfeeding.

From the shop

For later, no rush

Positive test? There is nothing you need to buy straight away. A pregnancy pillow will become precious in a few months for sleeping on your side, then for breastfeeding: here are a few models in different sizes and prices.

Products sold by La Maison du Bébé, publisher of this magazine. Prices as of 12 October 2026; please check the product page.

The test is negative but your period hasn't come. Repeat the test a few days later, or a week after your period was due. If the second test is still negative and you still have no period, see a doctor: they will look for another cause and may prescribe a blood test.

Frequently asked questions

Can a pregnancy test be positive before a missed period?

Yes, it is possible with so-called early tests, which detect smaller amounts of hCG, sometimes a few days before your period is due. But at that stage many pregnant women don't yet have enough hormone in their urine, so a negative result means nothing. For a reliable answer, wait until the first day of your missed period.

Do I need to fast for a pregnancy blood test?

No. Measuring beta-hCG in the blood needs no particular preparation: you can eat and drink normally beforehand. It is an ordinary blood test, taken from the crook of your elbow. The result is often ready in about a day. If other tests are on the same prescription, ask the laboratory whether any of those require fasting.

Can the pill or antibiotics affect the test?

No. According to the NHS and the Mayo Clinic, the pill and antibiotics do not change the result of a pregnancy test. Medicines that contain hCG, used in some fertility treatments, can however give a false positive. A few medicines that act on the nervous system can also interfere with a urine test: if in doubt, ask your pharmacist.

What does my beta-hCG level mean?

In a woman who is not pregnant, it is very low, under 5 mIU/ml. In early pregnancy it rises fast, roughly doubling every two days. Normal values vary enormously from one woman to another at the same stage, so a single figure says little. What matters is how it changes over time, as interpreted by your doctor.

My test was positive, then my period came: what happened?

It may have been a pregnancy that stopped very early, just after implantation, before it could even be seen on a scan. It is not your fault. Talk to your doctor about it, and without delay if the bleeding is heavy or painful, or if you feel pain on one side of your tummy.

Sources

  1. Doing a pregnancy testNHS · United Kingdom
  2. Ectopic pregnancy: symptomsNHS · United Kingdom
  3. Les tests de grossesseSanté.fr, French public health information service · France
  4. Home pregnancy tests: Can you trust the results?Mayo Clinic · United States
  5. Pregnancy testMedlinePlus, National Library of Medicine · United States
  6. HCG blood test - quantitativeMedlinePlus, National Library of Medicine · United States
  7. Guide de votre premier trimestre de grossesseUNICEF · International