How Pregnancy Tests Work

Pregnancy test are used to detect the presence of a hormone called Human Chorionic Gonadotropin (hCG).

There are Two Types of Pregnancy Test

• Urine

  • There are 2 ways to perform the test:
    • Dipping the pregnancy test kit into a urine sample.
    • Dropping 2-4 drops of urine sample to the pregnancy kit test.
  • If done correctly urine test are 97% accurate.
  • Can be done at home.
  • Inexpensive
  • Give fast result.
  • Easy to use.
  • Some may get a false negative result if taken too early or if done incorrectly.
  • If you still have the symptoms of pregnancy and a negative result was given by the urine test wait a week to take another test or you can have blood test done.

• Blood

  • There are 2 types to perform the test:
    • Quantitative Blood test
      • Measures the exact amount of hCG in the blood.
    • Qualitative hCG blood test
      • Provides  a simple yes or no answer to whether you are pregnant or not.
  • Advantages for the Blood Pregnancy Test:
    • Able to detect early pregnancy.
    • Determines the concentration of hCG hormone.
  • Disadvantages for the Blood Pregnancy Test:
    • Expensive than the urine test.
    • Need to wait longer for the result.
    • Needs to be done with a doctor’s order.

How common are false negative pregnancy for urine  tests?

• Most of the pregnancy test are 97% accurate. A false negative can happen due to test errors.
  • Follow the instructions of the pregnancy test.
  • Read the result within the time frame given to avoid confusions, don’t wait too long to read the result as it may provide a false negative result.
• If taken too early most likely you will have a false negative result.
  • It is possible that your hormone hCG in your system are too low to get a positive result.
• Not enough hormone hCG in the urine.
  • Level of hCG decreases if you drank too much water, diluting your urine.
  • It is recommended to take the test in the morning as hCG concentration is higher when you held your urine for awhile.

Is it possible to test positive and not be pregnant?

• A false positive pregnancy test can be devastating to people who are trying to conceive for a long period of time. Good thing, false positive are rare.
• Some factors that may provide a false positive result:
  • Reading the result beyond the time frame given on the instruction.
  • Expired pregnancy test kit.
  • Fertility medication increases hCG levels.
  • An early miscarriage.

Do early pregnancy tests work?

• Early pregnancy tests can never diagnose the presence of the hCG hormone until after implantation.
  • hCG is a hormone produced by the placenta.
  • Placenta starts developing at the time of implantation.
  • Implantation is the stage of pregnancy at which the embryo adheres to the wall of the uterus.

How many days are required to confirm pregnancy?

A week after your missed period, however if you can’t wait until you’ve  missed your period, wait at least a month or two after you had sex.

• The body needs time to develop detectable hCG level, which takes to 7 – 12 days after successful implantation.