Almost every girl at least once in her life took a pregnancy test. And no wonder, because it is a fairly convenient and quick way to find out about a possible pregnancy, with the help of a test from the first days. In this article, we will tell you more about what a pregnancy test is. When can you do it? and how it works.
How does a pregnancy test work?
Pregnancy tests work by testing your urine for a hormone called human chorionic gonadotropin (hCG). Your body only produces this hormone if you are pregnant. HCG is released when a fertilized egg attaches to the mucous membrane of the uterus. How does the pregnancy test show? Pregnancy tests convey how urine reacts with a sheet of paper, which can detect the presence of hCG. The results are usually shown as one or two lines and as a plus or minus sign. If the pregnancy test results are positive, it means you are pregnant. If they are negative, it means you are not pregnant.
When does the test show you’re pregnant? It usually happens about 6 days after fertilization. HCG levels rise rapidly, doubling every 2 to 3 days.
When is a pregnancy test done?
You can take a pregnancy test from the first day your period is late, which is when they work best. It’s a good idea to take an early pregnancy test as soon as possible if you miss your period or think you might be pregnant. You can find out what the first signs of pregnancy might be in our article.
Also, the time of day when you take a pregnancy test has some significance. You have a better chance of getting an accurate result if you take the test in the morning. This is especially important if you are not yet menstruating or if you are only a couple of days late.
How long should I wait before taking a pregnancy test?
Many pregnancy tests say they work a few days before your period is late, but the results are usually less accurate at that time. Read the label on the pregnancy test to find out when to take it and how accurate it is. When does a pregnancy test give a result? A pregnancy test can sometimes detect the presence of pregnancy hormones in the urine as early as 10 days after unprotected sex. But these results are not very reliable and you may get a false positive or false negative result.
If your period is very irregular or if you don’t know when your next period is, test at least 21 days after your last unprotected sex. Some very sensitive pregnancy tests can be used even before your period stops.
What is the right way to take a pregnancy test?
There are two of the most popular types of pregnant tests: the strip test and the inkjet or electronic test. Both tests can be used at home but in slightly different ways.
How do I use a pregnancy strip test?
Collect urine in a container and dip the reagent area of the test strip into it. After a few minutes, the test stick will begin to show a result in the form of red/blue stripes, “+”/”-” signs, or the words “yes”/”no”.
When can a pregnancy test result be false?
If you read the instructions carefully, most pregnancy tests promise 99% accuracy from as early as the first day of your period.
The accuracy of the test can depend on several variables:
- The timing of the test (tests are more accurate after a menstrual delay);
- The time of ovulation (when you ovulate and how soon the egg implants);
- How closely do you follow the instructions in the instructions;
- The timing of the test (what is the best time to take a pregnancy test? First morning urine can be more concentrated and more accurate in determining hCG);
- The sensitivity of the test.
Sometimes the result of a pregnancy test can be false positive or false negative, it depends on some facts.
Causes of false positive results
Pregnancy tests make a big difference. With one positive test, your whole life will change. But what should you do if you get a false-positive test? A false-positive test happens less than 1 percent of the time, but when it does, it can be confusing for the next days or weeks before you realize you’re not really pregnant. Why can a pregnancy test be a false positive?
- You recently had a miscarriage or abortion. After the embryo implants, it begins to secrete hCG, the pregnancy hormone. HCG is produced by the cells surrounding the growing embryo. The presence of hCG indicates a positive test result. How long after an abortion will the test be negative? After an abortion or miscarriage, hCG levels begin to drop within 9 to 35 days. If you take a pregnancy test in this interval, you may get a false-positive result because the test still detects the pregnancy hormone and cannot tell if its levels are dropping.
- A chemical pregnancy is a miscarriage that occurs before the fifth week of pregnancy when the embryo implants in your uterus but never takes root. The loss occurs so early that you may not even know you are pregnant. However, the embryo produces hCG and can cause a false-positive pregnancy test.
- Ectopic pregnancy. When an embryo embeds outside the uterus, this is called an ectopic pregnancy. Even if the embryo is not viable, it will still produce hCG, causing a positive pregnancy test.
- Infertility medications. If a woman has difficulty getting pregnant, her doctor may prescribe fertility treatments. Some of these medications include hCG, which helps follicles release mature eggs in a woman’s ovaries. If a pregnancy test is done within 7-14 days of fertility treatment, a false positive result may occur. It is recommended that pregnancy testing be delayed until 1-2 weeks after the last injection or treatment.
- Vapor lines. Sometimes a vapor line can be mistaken for a positive pregnancy test. Some home tests show two lines when hCG is detected and one line when no hCG is present. The lines are usually brightly colored, such as pink, red, or blue. Sometimes a second line of pale color appears. This line may indicate an early pregnancy or a vapor line.
- Other medical conditions. Sometimes certain medical conditions can cause a false positive pregnancy test before your period. If you have any of the following, they can inflate your hCG levels and you may get a false positive result: ovarian cysts; kidney disease; urinary tract infections; pituitary problems; and in some cases, ovarian cancer and other serious conditions.
Causes of false negatives
Home pregnancy tests are usually accurate, but researchers estimate that up to 5% of tests give false negatives – meaning that the test says you’re not pregnant when in fact you are. There are several reasons why you may get a false-negative result:
- The test has expired or you just got a faulty test.
- You took the test incorrectly. Read the instructions for the test carefully before you take it.
- You took the test too soon. Your pregnancy test should come with instructions on how long you need to wait between taking the test and checking the results – the waiting time is usually one to two minutes. This is because the antibodies in the test need time to detect hCG in your urine and display the result. If you check the test before the waiting time has expired, you may see a negative result even if you are pregnant.
- You took the test too early in your pregnancy. The amount of hCG in your body begins to increase as soon as the fertilized egg implants in your uterus and can be detected about 10 days after conception. Before that time, you may not have enough hormones to get a result, such as a negative test 1 day before your period. Or if your period averages 30 days, on day 26 of your cycle, the test is negative.
- You did not take the test in the morning. Urine has the highest concentration of hCG levels in the morning. If you cannot take the test in the morning, try using urine that has been in your bladder for about four hours.
- Your urine is too diluted. Drinking lots of fluids can dilute your urine and lower your hCG concentration, so it’s best not to drink too much water or other drinks before taking the pregnancy test.
- You are taking certain medications, such as diuretics or antihistamines.
