What Is A Pregnancy Test
A pregnancy test is a way to determine if youre pregnant by looking at the amount of human chorionic gonadotropin in your body. From the very beginning of pregnancy, your body starts to go through changes to support growth in the grouping of cells that will develop into your baby. One thing that happens very quickly is production of hCG. This chemical is only found in pregnant women and it starts to build up once the fertilized egg implants in the uterus about 10 days after conception.
There are two main types of pregnancy tests urine tests and blood tests. Often, youll take a urine test at home with a home pregnancy test kit. This type of test can be purchased over-the-counter and is available in a variety of price ranges. Blood tests to check for pregnancy are done in your healthcare providers office.
About Dr Roohi Jeelani
Dr Roohi Jeelani is Director of Research and Education at Vios Fertility Institute in Chicago, Illinois. Dr Jeelani earned her medical degree from Ross University School of Medicine in Portsmouth, Dominica. She then completed a residency in Obstetrics and Gynecology and a fellowship in Reproductive Endocrinology and Infertility at Wayne State University, Detroit Medical Center, where she was awarded a Womens Reproductive Health NIH K12 Research Grant. She is board certified in Obstetrics and Gynecology.
Getting It Right: Understanding Pregnancy Test Details
Details matter when it comes to getting an accurate pregnancy test result. Taking a pregnancy test at the wrong time, or using a pregnancy test incorrectly, can result in a false-negative or false-positive result.
The results from home pregnancy tests are up to 99% accurate the day after a missed period but may be less accurate at other times. Range in accuracy is due to a few factors:
- Correct use of a home pregnancy test.
- Knowing the first day of your last period.
- Knowing your ovulation and menstruation cycle dates.
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When Is The Best Time To Take A Pregnancy Test
Ovulation generally occurs around day 15 of a 28-day cycle. In a normal pregnancy, an egg is fertilized in the fallopian tube and then travels into the uterus, where it implants itself in the uterine wall. A womans body begins to produce hCG from cells in the developing placenta soon after implantation of a fertilized egg inside the uterus. Around eight days after ovulation, trace levels of hCG can be detected from an early pregnancy. That means a woman could get positive results several days before she expects her period to start.
The tricky part of timing when to take a test is that the duration of the first half of a menstrual cycle is more variable than the second. The length of time from the first day of a period to ovulation can vary by several days from month to month. Sexual activity around ovulation leads to the possibility of fertilization of the released egg by sperm. But even then, the time frame for a fertilized egg to implant can vary. And hCG isnt produced until after implantation has occurred.
For the most accurate results, we recommend that women test in the morning on the day they expect their period to start. This allows for variability in the timing of ovulation, fertilization, and implantation. Testing in the morning provides a urine sample that is concentrated.
Pregnancy Test Was Carried Out Too Early
If youve taken a test very soon after intercourse, it will result in a negative pregnancy test. Remember that your HCG level will need to rise and be detected in these strips. If you test before implantation occurs, it will come negative.
On the other hand, it possible that you will have symptoms of pregnancy and still test negative. This only means your HCG hormone is still low. It can happen sometimes and does not indicate you a problem.
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How Early Can Home Pregnancy Tests Show Positive Results
In the Aerosmith song Sweet Emotion, Steven Tylers lyric the rabbit done died refers to the original way a pregnancy test was performed one that literally killed rabbits. Urine from a woman who thought she might be pregnant was injected into a rabbit, which would then be surgically opened so its ovaries could be inspected. If the woman was pregnant, the rabbits ovaries would undergo noticeable changes due to the hormone human chorionic gonadotropin that develops early in gestation. The rabbit unfortunately didnt survive.
Thankfully, pregnancy tests have evolved substantially since the 20th century. Women now have access to advanced tests that can detect a pregnancy days before a missed period. In fact, a CBS News article outlined the best home pregnancy tests according to research from Consumer Reports, based on ease of use, ease of reading results, and effectiveness. Many tests today are marketed as simple and effective, but getting accurate results comes down to when the test is taken.
When To Get A Blood Test
You might be wondering if you should also have a blood test to check if youre pregnant. It is something to consider if you get a positive or negative result. Your doctor may order a test, or you may be thinking about ordering one yourself. Many labs now allow people to order and pay out of pocket for their blood work.
Before you do that, there are a few things you should know. First of all, there are two types of pregnancy blood tests: qualitative and quantitative.
- Qualitative tests measure whether hCG is present in your blood or urine. They pretty much give a yes or no answer as to whether youre pregnant. Or, more accurately, whether you have enough pregnancy hormone to get a positive result. Home pregnancy tests are qualitative.
- A quantitative pregnancy test measures the amount of pregnancy hormone in your blood. This is sometimes called a beta hCG test. These are usually done to see how a pregnancy is progressing. For example, your doctor may order a beta hCG test on Monday, and then another test on Wednesday or Thursday. The purpose would be to see whether the level of hCG is increasing as expected or not. This might be important if you had trouble conceiving, have a history of early miscarriage, or an ectopic pregnancy is suspected.
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When Is The Best Time Of Day To Take A Pregnancy Test
The best time of day to take a pregnancy test is first thing in the morning because at that time your urine contains the highest concentration of hCG. This is particularly important the earlier you are taking your pregnancy test. You can test later in the day, but you will have a higher chance of seeing a false-negative test result because your urine will be diluted. Tips for testing include:
- Use first-morning urine .
- Dont drink a lot of fluid that could dilute your hCG levels before your test.
- Check to make sure the pregnancy test is not expired, which can provide inaccurate results. Checking the expiration date is particularly important if you keep pregnancy tests at home just in case.
- It is understandable that once you have the pregnancy test in your hands, you want to get to the answers quickly. Plus, it seems like a no-brainer because they are designed to be easy to use. Take time to read all of the instructions and follow them precisely. Even if you have taken pregnancy tests before, little variances between them can be the difference between a result you can count on and a wrong one.
- We all know how easy it is to lose track of time, so do not try to estimate when to read your results. Set a timer so you can read your test results exactly at the time directed in the instructions. Do not read the test window after that set time because a faint evaporation line can appear, which makes your test appear to be positive when it is really negative.
If You Dont Know When Your Next Period Is Due
You might not have tracked your period before, but you have an opportunity to track it now! This time youre going to track the days since you had unprotected sex.
Its also a good move to take the test again after 12 days have passed since the sex.
Blood vs. urine test
Blood tests offer slightly more accurate results, and can tell you youre pregnant before your missed period, Copperman says. The downside is that it takes longer to receive the results . That said, urine tests are still pretty darn accurate. Urine tests are accurate 95 to 99 percent of the time, compared with the blood tests 99 percent.
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What If I Can’t Tell Whether My Pregnancy Test Is Positive Or Negative
Sometimes it can be hard to tell whether the test is positive or negative. The line may be faint, or you may worry whether you peed too much or too little on the stick.
No matter how faint the line or plus sign, if you see it, you are most likely pregnant. The faintness of the line can mean you are early in your pregnancy and your hCG levels are still low.
Also, the pregnancy test should have a control line that tells you whether the test was done correctly. If the control line is blank, then the test did not work and you should take another test.
Are Early Pregnancy Tests As Accurate
The hormone hCG is manufactured by the placenta and first appears in your urine anywhere from 10 to 14 days after fertilization. But while hCG increases rapidly in the first few weeks, not everyone produces the exact same amount on the exact same timeline. Because of this and because its possible for your cycle to vary slightly from month to month, its not uncommon to get a false negative. If you ovulated even just a day or two later than normal, a negative test might not actually be a negative, says Gilman.
The longer you wait for testing, the more accurate its going to be, adds Taylor. She recommends waiting to testat least until youre expected periodto get the most accurate result possible.
To help minimize your odds of getting a false negative, Taylor says to test using your first urine of the day. Unless you have a tendency to visit the washroom frequently during the night, your hCG will be at its highest concentration in your first urine and give you the best shot at an accurate result.
If you test early and get a negative sign, hold off on reaching for that bottle of wine. Until you get your period, you should at least assume that theres a chance that youre pregnant, says Gilman, who recommends that you retest again on or closer to the date of your expected period.
But a positive test means youre pregnant, says Taylor, who adds that theres no need to retest.
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When Should I See A Doctor For A Clinical Pregnancy Test
Most women who have a positive pregnancy test should wait a week or two before calling the Ob/Gyn office for a pregnancy blood test. We suggest waiting because the rate of early pregnancy loss is high, and its possible that it might have been a chemical pregnancy.
However, women with a history of ectopic pregnancy or current abdominal pain should call the doctor right away to be examined. Ectopic pregnancies implant outside of the uterus and produce hCG, resulting in positive pregnancy tests. However, these pregnancies can cause abdominal bleeding and prompt medical care is necessary. Women who have congenital heart defects or other chronic physical or mental health conditions should also see a doctor right away because treatment plans or medications might need to be altered to protect the woman and the fetus.
Advances in home pregnancy tests give women greater insight into whats going on in their bodies sooner than ever before. No matter what a womans childbearing plans might be, its essential to get quick, accurate results at home so she can plan her next steps accordingly.
What Colour Of Urine Indicates Pregnancy
If you are pregnant, you must have noticed a distinct change in the colour of your urine. Typically, pregnancy urine colour can change from yellow to a brighter or darker shade of yellow. Such changes not only indicate pregnancy health but also alert you of any complications over the course of nine months.
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What Can Cause Pregnancy Tests To Be Wrong
Each type of pregnancy test is designed to detect a set minimum level of hCG. This is why pregnancy test manufacturers advertise the way they do: Know four days sooner, or Accurate up to six days before a missed period. However, while home pregnancy tests are quite accurate many boast a 99 percent detection rate based on laboratory testing results marketing claims can be misleading. For example, a 99 percent detection rate means a test can detect hCG 99 percent of the time on the day a woman misses her period. These statistics also assume that women are testing at the optimal time, following all instructions, and fully understanding how to interpret the results.
In reality, its not that easy. Some studies suggest that up to 1 in 4 tests could be misinterpreted, which has led some companies to switch from using the presence of lines or colors to indicate a positive result to using actual words such as yes, no, pregnant, or not pregnant for clarity.
When a test result is inaccurate, its either a false negative or a false positive . Several factors can cause false negative results:
Having too dilute urine after drinking a lot of water or testing later in the day.
Testing too soon when there has not been enough time for an early pregnancy to implant and start producing hCG.
Using a pregnancy test that doesnt detect lower levels of hCG. You can check the package insert for more information about the level at which the test will be positive.
When Should You Take A Home Pregnancy Test
Most home pregnancy tests advise you to take the test after you miss your next period. If you have a standard 28-day cycle, you’ll be most fertile two to three weeks before your period.
So if you get pregnant during that fertility window, you’ll need to wait at least 14 to 18 days after conception to take a home pregnancy test.
If you get a negative result and suspect you’re pregnant, check the instructions on the box. Home pregnancy tests typically recommend retaking the test 5 to 7 days later, when the hCG levels in your body will be higher.
This type of result is called a “false negative.” Sometimes you can receive a false negative result if you take a pregnancy test too soon when your hCG levels are too low for the test to detect them accurately.
Moreover, recent miscarriages, fertility drugs, and rare hCG secreting tumors can interfere with the results of at-home urine tests. If you receive conflicting results after taking a home pregnancy test multiple times, doctors recommend a blood test.
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Ovulation Fertilization And Implantation
While youre probably familiar with the mechanics of how a baby gets madeAKA the fun part of reproductiontheres an extraordinary series of events that need to happen inside the mom-to-bes body in order for a home pregnancy test to display a positive result.
Heres how that breaks down:
- Ovulation Many people may mistake an ovulation test as pregnancy test, but they are not the same. Ovulation is a biological process in which a mature egg leaves a womans ovary and drops down into the fallopian tubethe tube that connects the ovaries to the womb. During ovulation, your body is at its most fertile. Its the fertile period when an egg can turn into an embryo, the cellular beginnings of your bundle of joy.
But youll need more ingredients than an egg to make a bun in your ovenso to speak.
Youll also need a little help from sperm.
- Fertilization To create an embryo, youll need two gametes, or cellular reproductive components: the egg, which is a maternal reproductive cell, and sperm, the paternal reproductive cell. When sperm are released into a womans vagina through intercourse, they seek out their other halfthe egg. But only one sperm can make it all the way through the vaginal canal, into the uterus, and up to the fallopian tube to fertilize the egg. Additionally, an egg is only viable for fertilization for 12-24 hours after ovulation, so timing is critical.
Early Pregnancy Test: How Soon Will A Pregnancy Test Read Positive
A home pregnancy test detects the presence of human chorionic gonadotropin , which is produced in a pregnant woman. Traces of hCG can be seen in urine 3-4 days after the fertilized egg implants in the uterus, and the amount doubles every 48 hours. When there is enough hCG in the body, a pregnancy test can detect it and produce a positive result.
If your periods are irregular, however, and your test result is negative, you should repeat a home pregnancy test after 1 week.
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