Pregnancy Test

A pregnancy test is done to determine if you are pregnant or not. In this, you check for the presence of a hormone, called human chorionic gonadotropin (HCG), in your body. HCG is only produced during pregnancy. The placenta in the woman’s body starts producing them after the fertilised egg attaches to the walls of the uterus. Once your body starts producing it, the level of HCG rises very quickly, doubling every two to three days.

There are two ways you can take the pregnancy test: through urine, or blood, in both of which the presence of HCG is checked. The urine pregnancy test is generally taken a week after you miss your period. It can be taken under medical supervision or at home and is accurate 97-99% of the time. The blood urine test is taken in a medical centre. Through this, even a very small amount of HCG can be traced. It is quick and efficient as it gives the result before the urine test result, and even before you miss your period. It has an accuracy rate of about 99%. It is generally taken to confirm the urine test result.

What Are The Options?

As you already know, there are two types of pregnancy tests: blood and urine. Now, let us look at them one by one:

Blood Pregnancy Test

This has to be taken in a clinic. A small amount of blood is drawn from the veins of your arm and is then sent to a lab for testing. A blood pregnancy test is of two types:

• Qualitative HCG test: In this, the doctor simply checks if there is a presence of HCG or not, to determine if you are pregnant or not.
• Quantitative HCG test: In this, the doctor tests the exact amount of HCG in your blood. Even the smallest amount of the hormone can be tested. It determines how far you have progressed in your pregnancy. It also figures out pregnancy-related complications, such as miscarriage, in which case the HCG level drops very quickly.

Urine Pregnancy Test

You can take the urine pregnancy test at home or at the doctor’s office. Both work the same way. If taking one at a clinic, you will be required to pee in a cup. The doctor will then use a kit, similar to a home pregnancy kit, to determine the presence of the HCG hormone, to confirm if you are pregnant or not.

When To Take A Pregnancy Test?

You should take a pregnancy test if you think you are pregnant. Here are some early signs of pregnancy:

• A missed period is the primary sign of pregnancy. However, you should wait for at least a week after you miss your period before taking a pregnancy test. There can be other reasons for a missed period too, such as stress, diet, or if you suffer from polycystic ovary syndrome (PCOS). Also, do not light bleeding, and spotting are common during the initial phase of pregnancy.
• If your breasts get large, swollen, and tender. Your nipples might hurt, and the veins in your breast might get tender.
• If you have to urinate frequently
• If you have vomiting and/or nausea, in other words, morning sickness
• If you have cramps similar to menstrual cramps
• If your abdomen feels bloated
• If you have developed an aversion to foods that you earlier enjoyed
• If you constantly feel tired.

Home Pregnancy Test

You can get a home pregnancy test at a medical store and you do not need a prescription for it. It is inexpensive and widely available. Most home pregnancy test kits have a device called a dipstick. They might also contain a collection cup. These tests are accurate 97% of the time. However, it might give a false result, generally if taken too soon after you miss your period. Hence, do note that you should wait for at least a week after you miss your period before taking a pregnancy test.

• The steps in the case of home pregnancy tests are generally the same and are available on the box. However, here are some common steps you can follow:
• Pee in the collection cup and dip the test stick in it. In some home pregnancy test kits, you might have to pee on the test stick.
• The best time to take a pregnancy test is right after getting up in the morning. This is because the urine gets concentrated during the 6-8 hours of sleep and contains a high amount of the HCG hormone.
• The test kit will show results in just a few minutes, however, the time required varies from kit to kit. 
• Many pregnancy test kits have a second stick that helps you confirm the results of the first one. 

If your pregnancy test result comes out to be positive, it means you are pregnant, and vice versa. If positive, you must immediately see a doctor understand what to do next and how to prepare. The negative test result means you are not pregnant. In that case, too, it might be good to see a doctor to understand why you missed your period. There can be several reasons behind a missed period:

• If you are under stress or anxiety
• If you are obese
• Poor diet
• Lack of exercise
• If you are on a certain medication
• Polycystic ovary syndrome, or PCOS, causes irregular periods
• The missed period might also indicate the onset of menopause

False Results

Although both urine and blood pregnancy tests are accurate over 97% of the time. However, there is still a 3% chance that it might come out to be false. 

False Positive Result

In some cases, the home pregnancy test might give a positive result, even if the woman is not pregnant. Here are some of the possible reasons behind it:

• If the pregnancy test kit is faulty. It can get faulty if gets damaged, is exposed to heat or moisture, or is past its expiration date.
• If you recently gave birth or had a miscarriage. This is because the body still has some amount of the HCG hormone even after delivery and miscarriage.  
• If the collection cup is dirty. For example, it has a detergent residue that might lead to a positive result. 
• If there is blood in the urine. 
• If there is protein in the urine, such as because of a kidney ailment.
• If you are on certain medications.
• It might also come out to be positive in case of ovarian tumour, or some other ailment that causes the release of HCG hormone. 

False Negative Result

Just as the home pregnancy test kit can give a false positive, it can give a false negative result too. Here are some of the possible reasons behind it:

• If you take the test too early, i.e. within a week since missing your period. This is because, during this time, the level of the HCG hormone in your body is still too low to be detected by the kit.
• If you do not wait for enough before determining the result. Most pregnancy test kits take at least a few minutes before displaying the result. 
• If you read the test result incorrectly. On how to read the test result is always given on the box, so you must refer to it.
• If you drank a lot of water or other fluids before taking the test. This is because your urine gets diluted and the HCG level gets difficult to be detected. 

If even after the negative result, your instinct says you are pregnant, you should always trust it. Take another pregnancy test, or visit the doctor to get the blood pregnancy test, which is more accurate. Also, treat yourself as pregnant until you are completely sure. 

https://www.betterhealth.vic.gov.au/health/healthyliving/pregnancy-testing#home-pregnancy-test-kits

https://medlineplus.gov/lab-tests/pregnancy-test/

https://www.nhs.uk/pregnancy/trying-for-a-baby/doing-a-pregnancy-test/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4119102/