Testing for pregnancy is a simple activity but getting an accurate result is more important and that is dependent on some factors.
The time you test for pregnancy is one of the major factors that contribute to the accuracy of the result.
Generally, it is advised that you test for pregnancy after you have missed your period, but what happens when you cannot remember your period dates or you have an irregular menstrual cycle?
There is still a way to figure out if you are pregnant even when you don’t remember your cycle, and of course, you can detect that relatively early.
Understanding how pregnancy and fertilization begin and how pregnancy is detected are 2 major pieces of information that you will need to aid you in testing pregnancy accurately.
How and when does pregnancy begin?
You have just had unprotected sex. Every unprotected sex has the potential of getting a woman pregnant, especially when it is during her ovulation or close to her ovulation.
When a man penetrates your vagina and releases some semen into you, the semen carries millions of sperm.
This semen flows down into your vagina and one of the sperm fights to fertilize an ovum in the fallopian tube.
Watch the video below for a demonstration of how this happens.
The process of fertilizing the egg might not be as quick as we may think.
If you are ovulating
Once the sperm reaches the egg, the egg is not immediately fertilized. The sperm will go through a process called capacitation, this process is estimated to last for about 10 hours. Adding up the time of journeying to the ovum with the time for capacitation gives us about 11 hours.
This is the reason some approximate the fertilization duration to be 24 hours, particularly for ovulating women.
This happens because the egg is already there, waiting to be fertilized.
If you are not ovulating
There is no egg ready to be fertilized, so the sperm will have to live in your reproductive tract for a while. How long the sperm will live is not cast in stone, but generally, sperm can live for about 2 – 5 days.
If within 5 days, an ovum is released fertilization occurs. So if we add the 10 hours of capacitation to 5 days which is the maximum a sperm can live for that takes us to around 6 days. The fertilization can as well take 1 day and 10 hours, 2 days and 10 hours as the case may be.
What next?
After fertilization, the next process is implantation.
Implantation is said to happen in about 6 – 10 days after fertilization has taken place.
Let’s have some arithmetic.
If the woman is not ovulating
If we take the max duration for fertilization, of course, in a case of a woman who has unprotected sex when not ovulating, we have 5 days. Again, when we also take the max implantation duration we have 10 days.
Min fertilization duration = 5 days
Max Implantation duration = 10 days
Total = 15 days.
This is the likely reason some experts recommend taking pregnancy tests after 2 weeks of sexual intercourse when you don’t remember your menstrual cycle.
If the woman was ovulating
The arithmetic is different.
Max fertilization duration = 45 minutes (for moving into the fallopian tube) + 10 hours for capacitation – 11 hours in all (approximately)
Max implantation duration= 10 days
Total = 11 days.
This is probably the reason some believe that pregnancy can be detected 10 days after sexual intercourse (11th day from Sexual Intercourse).
We factored that into this calculator but we based it on a 50-50 chance because the pregnancy may as well not be detected.
Before I proceed, remember that we used the maximum durations, all of these could be shorter. The implantation can happen at least 6 days after fertilization. If that happens, both fertilization and implantation would have taken 7 days.
By the 10th day, pregnancy test kits might be able to detect pregnancy. But there is also a chance that they will not.
Why?
Because of HCG.
What is HCG?
HCG (Human chorionic gonadotropin) is a hormone produced during pregnancy by cells in the placenta. It tells the body to make progesterone, which helps keep the pregnancy healthy.
What pregnancy home test kits do is test for the presence of HCG in a woman’s urine. HCG can also be detected in the blood.
The accuracy of the pregnancy test depends on the quantity of HCG the body has produced, at an early stage, the body might not have produced sufficient HCG for the test kit to determine.
Below is the quantity of HCG and what it may mean.
- Negative: less than 5 IU/L
- Indeterminate: 5 to 25 IU/L
- Positive: greater than 25 IU/L
According to the National Library of Medicine, HCG can be detected in a woman’s blood about 10 days after fertilization. We can safely assume that by this time, implantation has also taken place.
Another source (Reunite) claims that in
about 11-14 days after implantation, a woman’s hCG levels are high enough to start causing early pregnancy symptoms.
Reunite
Going back to our calculations.
If the max duration for fertilization is 5 days and a woman’s egg gets fertilized on the 5th day, 10 days after that the pregnancy can be detected through the presence of HCG and that will be about 14 days after sexual intercourse. If fertilization took place within 24 hours, the HCG can be detected after 10 days.
As you might have guessed, the longer a woman goes into pregnancy the more HCG is produced and the easier pregnancy is to detect. According to Reunite, “Within one day of implantation, hCG levels increase by 50% every day.”
In essence, waiting for the maximum estimated periods of both fertilization and implantation will yield more accurate results.
Women with Irregular Period
Navigating the right timing for a pregnancy test can prove challenging, particularly for individuals with irregular menstrual cycles. In such circumstances, achieving accuracy requires a thoughtful approach. Consider taking the test approximately 21 days after engaging in sexual intercourse to enhance the reliability of the results. By doing so, you’ll ensure better clarity in this pivotal moment of uncertainty. Remember, each person’s body is unique, and seeking professional advice is always wise when it comes to matters of reproductive health.
How to Use This When to Test for Pregnancy Calculator
Here is a step-by-step guide on how to use our when to test for pregnancy calculator.
The first step when you get on the calculator, you will be asked if you know your menstrual period, if you click yes, you will be taken to a point where you will be asked to type in the first day of your last period it’s in the format, month, day and year.
Next, you will be asked how long is your menstrual cycle, the menstrual cycle starts from 21 to 35 days, pick the day yours fall into, and the pregnancy test day calculator will give you an estimate of when to take the pregnancy test as long as you missed your period the day before.
On the other hand, if you click on no when you are asked if you know your menstrual period, you will be asked to type in the date of when you last had sex, it still follows the month, day, and year pattern.
Next,
you get to select how accurate you want the result to be by dragging the button to the percentage of accuracy you want, the number of days after sex is solely dependent on how accurate you want the result to be. After determining that, our pregnancy calculator will estimate when you should take the test.
For instance:
If you chose ‘yes’ to the “Do you know your menstrual period”?
Type in 04/06/2023 as the first day of your last period
Pick 28 as how long your cycle is, the pregnancy testing day calculator predicts that the estimated date you should take your pregnancy test is on Saturday, 20 May 2023, that is if you missed your period the day before.
IF NO is your answer to the question “Do you know your menstrual period”?
Say you pick 04/02/2023 as the last sex date, and you picked the accuracy of the result to be 85%, the number of days after sex is determined to be 18, and your estimated day of taking a pregnancy test as predicted by the calculator will be on the 9th of May 2023.
So, How Soon after Unprotected Can I Test for Pregnancy Calculator?
The short answer is within 10 – 14 days after sexual intercourse.
If you wait longer for about 21 days, you get a 99% accurate result.
Even though home test kits have been proven to be effective home test the most reliable testing method is a pregnancy blood test in a laboratory.