How Soon Can I Take A Pregnancy Test?

It's probably one of the most-asked questions we receive here by email. Everyone wants to know: "How soon can I take a pregnancy test?" Of course, there are a number of variations on this question, particularly for women who are fertility charting and who want to know - exactly - at how many days past ovulation they can begin testing (and hopefully get that earliest positive result). Below, we'll look at all the facts and details relating to answering this question - and give you the most informed framework for hazarding a "best guess" on when you can begin!

Question: When Can I Take A Pregnancy Test? And the answer is.... that depends! Yes, as with all good questions, there is never a good, easy, simple one size-fits all answer. But we will be happy to provide you with all the variables involved in answering this question for yourself, and hopefully this can give a relatively good picture for a time frame for testing.

The Variables Involved in Pregnancy Testing:

1. The HCG Sensitivity of a Given Test

2. The Rate of hCG Production

3. Urine Dilution / Consumption of Liquids

4. What Time of Day You Test

5. Do You Know When You Ovulated?

6. Actual moment of "Implantation"

Let's begin with some background info. A pregnancy test functions by homing in on one specific reproductive hormone that starts flowing through your body the moment you become pregnant. This is not the moment of conception, however. Conception is when a sperm and egg unite (aka fertilization). The fact is that a pregnancy is "inaugurated" not at the moment of fertilization, but when a fertilized egg actually "hooks up" to your womb. That is the moment you are pregnant, and the time that this unique hormone (hCG) is able to flow from the placental tissue into the bloodstream of the mother. From the blood, the hCG circulates through the body and ends up in the urine as well.

Ovulation and Implantation: Now, here's the confusing part that makes answering this big question of "When Can I Take a Test" a bit difficult. Once the egg is fertilized, it floats around for a few days - even up to a week or so - before it is able to nestle its way into a comfortable home in the uterine lining (or wall of the womb). Theoretically, if you ovulate on Cycle Day 14, and you "conceive" on day 14 or 15, the embryo will just be hanging around looking for that special place to snuggle up into the womb. It's possible that your implantation date can take place just a handful of days after conception. But it's also possible that it can take up to a week or more! Thus, it is not possible to pinpoint a specific day when you can test and get that long-sought-for positive result. However, if you know when you ovulate (thanks to ovulation tests) you can still better focus in on a pregnancy test start date.

hCG Levels: The next crazy variable to confound us in seeking an answer to the big question is how fast hCG increases in your system. The fact is, different embryos will produce hCG at a faster or slower pace, depending on the woman and where the embryo implants. This means that for some women, hCG levels will rocket and for others it may trickle a bit at first. The good news here is that the amount of hCG in your body will increase rapidly - and double almost daily. This is called the doubling rule, the exponential increase of the hormone, and it means that even if hCG production is lower for some women, it won't take too much longer for the amount to reach the threshold required for a pregnancy test to detect the presence of the hormone in blood or urine.

Test Sensitivity: The next variable can be controlled when you purchase a test. In the past, most tests had lower sensitivity thresholds, meaning that they required you to wait at least until your missed period to begin taking a test. Many tests still ask you to do so. However, newer FDA-Approved products do allow you to test before your missed period, including certain drugstore tests like First Response and affordable, high-sensitivity test kits available online. The highest (reasonable) threshold is 20mIU/ml/hCG. This means that the amount of hCG in a given urine sample must exceed this "trigger" level for a positive test line to be produced. So, using higher sensitivity tests, the answer to the big question is: You may begin testing at around seven to ten days past ovulation. But wait!!! As noted above, variables like implantation date and rate of hormone production do not guarantee a positive result during this early testing window. According to research data, it's likely that you may first see a positive pregnancy test during this time, but a negative result is still possible and does not close out the possibility of pregnancy. It's wise and recommended to conduct follow up tests!

FMU and Hold Time: Okay, so we now have a kind of fuzzy time-frame for knowing when to start taking a pregnancy test. At this point, we can look at other variables to help ensure that we can increase the accuracy of the result. These are factors we can control simply by following the directions in the instructional insert and taking certain steps to ensure that the hCG in a given urine sample will be at its highest levels. If you have been around this website, then you already know that testing with First Morning Urine is the first big factor in getting the earliest positive test result. First morning urine will exhibit a higher concentration of the hormone than samples collected at other times of the day. That's because all night, while you have slept, hCG has been allowed to accumulate in your urine. Now, if you do end up testing during other times of day, there are some things you can do to increase result accuracy. First, in the hours before you "pee for a test", try to avoid flushing the body with a lot of liquids. Never dehydrate yourself! Just take it easy on the liquids and hold your urine as long as possible before you collect a sample or pee on that stick.

If you are trying to conceive and are fertility charting, then you will know the approximate date of ovulation. With that fact, you can pretty much determine the approximate days for when you can take a pregnancy test. Best of luck and babydust to all!