Home pregnancy tests

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Home pregnancy tests

• What is a home pregnancy test?
• A home pregnancy test detects the presence of the
  pregnancy hormone, human chorionic gonadotrophin
  (hCG), in your urine.  Your body starts to
  produce hCG when a fertilized egg implants in
  your uterus (womb). HCG is secreted by the cells
  which will go on to form your baby's placenta. It
  can be detected in your urine from about six to
  14 days after fertilization.
•  
• In the first few days after implantation your
  levels of hCG rise quickly. Most home pregnancy
  tests are sensitive enough to detect hCG in your
  urine on the first day your period is due.

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• If you have a negative result when you first
  test, it may be that the amount of hCG has not
  yet reached a level where it can be detected.
  Sometimes levels may still not be high enough to
  detect on the day your period is due. If your
  period is late, and the result is negative, wait
  a few days then test again. You will find some
  pregnancy tests are more sensitive than others.
  The most sensitive tests can tell you're pregnant
  even if you have only a small amount of hCG in
  your system.
• You can find out how sensitive a home pregnancy
  test is by reading the information that comes in
  the test box. You will see that concentrations of
  hCG are reported in milli-International Units
  (mIU) per milliliter. A test with a sensitivity
  of 20 mIU/ml is more sensitive than one with a
  sensitivity of 50 mIU/ml.

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• When should I test?
• Most tests can tell whether you're pregnant on
  the first day of your missed period. The more
  sensitive tests may be able to detect low levels
  of hCG a few days before your period is due.
  However, testing this early may not give you an
  accurate result (see below). Depending on the
  test you're using, you can test at any time of
  day. When you decide to test, try not to drink
  too much beforehand, as it could dilute the
  levels of hCG in your urine. Some tests may
  recommend that you use the first urine of the
  day, particularly when testing early. Levels of
  hCG become more concentrated in your urine
  overnight. If you have irregular periods, it may
  be harder to calculate when your period is due.
  Allow for your longest cycle in recent months
  before testing. If you have recently stopped
  taking the pill, you may not know how long your
  natural cycle is, and may end up testing either
  too soon or too late. If your test is negative,
  you should test again in three days.

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• How do I use a home pregnancy test? 
• First, read the directions carefully, because the
  instructions will vary with different brands. For
  many tests, it's as simple as passing urine on a
  test stick. For others you may have to catch your
  urine in a small cup, and dip a testing strip
  into your sample. Or, you may be given a dropper
  to place a small sample into a testing well. How
  test results are displayed can vary too. Some
  show pink or blue lines on the test strip. Others
  reveal a plus or minus sign, or change the color
  of your urine sample. Digital tests display the
  words "pregnant" or "not pregnant" in a window
  and some may give an estimate of how many weeks
  ago you conceived. Positive pregnancy test
  result negative pregnancy test result Here is an
  example of a positive result here is an example
  of a negative result

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• How long does it take to see the results? 
• Check the instructions with your test, but you
  should see the results in about three to five
  minutes. It can feel like the longest wait ever.
   
• If you're testing in the bathroom, you may want
  to go to another part of the house, and find
  something to do as a distraction. A watched pot
  never boils, and a watched pregnancy test is just
  as excruciating. 
• Are home pregnancy tests accurate?
• Home pregnancy tests are accurate if you follow
  the directions to the letter. Having said that,
  some tests are more sensitive, and easier to use
  and interpret, than others.

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• Is it possible to get a false negative?
• There are several reasons why a home pregnancy
  test may be negative. You may not be pregnant, or
  you may not be making hCG at a level that a urine
  test can detect yet. If you test too early,
  before the first day of your missed period, you
  may get a false negative result because not
  enough of the hormone has built up in your
  system.  If the test comes back negative but you
  still suspect you're pregnant, wait at least
  three days, and try testing again.  
• Is it possible to get a false positive?
• False positives, when the test says you're
  pregnant but you're not, are rare but not
  impossible. Some medicines such as fertility
  drugs, which contain hCG, may affect the test
  results. (Over-the-counter-medicines, such as
  paracetamol, should not.) Sometimes you may get a
  faint line which can be difficult to interpret.
  Find out what this may mean.
• Where can I buy a pregnancy test?
• You can buy pregnancy tests, without
  prescription, at most chemists. You can also buy
  them online.

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• How are home pregnancy tests different from ones
  performed by doctors?
• Many doctors use home pregnancy tests to confirm
  pregnancies, in which case they're exactly the
  same.
• Occasionally, women are given blood tests, which
  also test for hCG. A blood test is much more
  sensitive than a urine test. It can tell whether
  you're pregnant as soon as your fertilized egg
  has implanted. This could be as early as six days
  after you ovulate.
• You may have a blood test to get a better idea of
  what is happening in very early pregnancy (before
  an ultrasound can pick up on a pregnancy). It can
  help detect an ectopic or molar pregnancy. It's a
  good way to detect that the level of hCG is
  rising in a way expected for a healthy pregnancy.