Counting the days post ovulation (DPO) gets you to the end of the two-week wait, which gets you to a pregnancy test. But what does all of this mean for your body and your journey to pregnancy?
trying to conceive (TTC), you’re probably monitoring your menstrual cycle, your ovulation, and maybe even your hormone levels pretty closely.
You may have already heard the acronym “DPO,” or “days past ovulation,” and the phrase “
two-week wait” in and around your conversations about fertility. And while you might know that DPO has something to do with ovulation, and the two-week wait presumably means you have to wait for something for—you guessed it—two weeks, it may be less clear what the two actually mean.
So how do ovulation, DPO, and the two-week wait fit into your cycle and your TTC journey? Let’s find out.
What is ovulation?
To understand DPO, you have to understand ovulation.
Ovulation is the part of your menstrual cycle when a mature egg is released from one of your ovaries. While the exact timing varies from person to person, ovulation generally happens around the midpoint of your cycle.
The egg then travels down the fallopian tube. An egg can remain in the fallopian tube for
12 to 24 hours. This is part of the period of time when you can get pregnant, also known as your “ fertile window.” The fertile window generally lasts six days: it starts five days before you ovulate and ends on the day of ovulation.
Sperm can stay in the fallopian tubes post sex for
up to six days. If that period of time overlaps with ovulation, your egg may just meet up with sperm. If this happens, the fertilized egg makes its way to your uterus, implants into the thickened uterine lining, and you become pregnant.
If the egg isn’t fertilized, it disintegrates and your body sheds the thickened uterine lining during your period. Your period generally happens about two weeks after ovulation.
What is DPO and how does it fit into my cycle?
The days post ovulation, or DPO, happen during the
luteal phase of your menstrual cycle, after you ovulate.
1 DPO is the first day following ovulation, 2 DPO is the second day following ovulation, and so on.
To make things clearer, let’s look at an example of someone who ovulates on a Monday:
Ovulation: Monday 1 DPO: Tuesday 2 DPO: Wednesday 3 DPO: Thursday 4 DPO: Friday
The DPO count continues all the way to the first day of your next period, generally about two weeks (or 14 DPO) later – that is, if you haven’t gotten pregnant and your next period comes as scheduled.
What’s going on in my body at different DPO?
If you’re TTC, you most likely had sex during your fertile window, around the time you ovulated. During your DPO, you might be breathlessly counting down the days until you can take a pregnancy test.
Being patient is hard, but it’s also important. You
don’t get pregnant immediately after sex. In fact, depending on where you are in your cycle, it can take anywhere from two to three weeks after sex for an egg to be fertilized, travel to the uterus, and implant in the uterine lining – all of which has to happen for you to get a positive result on a pregnancy test. >>RELATED: How Long Does It Take To Get Pregnant?
Keep in mind that you can have sex prior to ovulating and still conceive. However, it’s important to understand the difference between days post ovulation and days post sex. Regardless of when you had sex, whether it was before or during ovulation, your DPO count doesn’t start until the day after you ovulate.
The span of time after ovulation and before your next period would normally come is often referred to as the “two-week wait,” because your period—if you get one—generally comes around 14 DPO.
Imagine you’re TTC and had sex during your fertile window. Here’s what’s happening in your body leading up to 14 DPO.
You just ovulated yesterday and the luteal phase just started. You’re also at the end of your fertile window.
You can still get pregnant at 1 DPO, but it’s less likely than conceiving on the actual day of ovulation. Remember how the egg released from your ovaries can remain in your fallopian tube for 12 to 24 hours? That means at 1 DPO, that egg is almost at the end of its viability.
The paths of a fertilized and unfertilized egg separate around 1 DPO. If the egg meets some sperm, it gets fertilized and starts to transform. If the egg is not fertilized either during ovulation or at 1 DPO, it starts to disintegrate and can no longer lead to a pregnancy.
Around 4 DPO
If the egg released in this cycle was fertilized, the resulting zygote (a fertilized egg cell) takes about three to four days to travel down the fallopian tubes, becoming a morula while on its journey.
By around 4 DPO, the morula has reached your uterus.
Around 6 DPO
The morula in your uterus becomes a blastocyst around 5 or 6 DPO.
A blastocyst is a rapidly dividing, hollow ball of cells. Later, these cells develop the embryo and the placenta.
Now that it’s in your uterus, the blastocyst floats around for a few more days. Even though there’s currently a fertilized egg in your uterus, you’re not yet pregnant at this point.
Around 8 DPO
The blastocyst then burrows into the thickened uterine lining in a process called implantation. Not all blastocysts implant.
Implantation usually starts around 8 or 9 DPO depending on when you conceived, although it can happen anywhere from 6 to 12 DPO. Implantation takes a few days to complete.
Around 12 DPO
Around 10 to 12 DPO, the blastocyst has implanted in your uterine lining and become an embryo.
Pregnancy officially begins after implantation. However, at 12 DPO, it’s still too early to take a pregnancy test. This is because the pregnancy hormone human chorionic gonadotropin (or HCG, the hormone produced by the placenta and measured by pregnancy tests to determine if you’re pregnant), isn’t yet present in high enough amounts to be picked up by a test.
15% to 20% of people may notice implantation bleeding, or light spotting, between 10 to 14 DPO. Implantation bleeding is not a cause for concern.
This spotting tends to happen around the same time you might expect your period, so it can be confusing to distinguish between the two. However, implantation bleeding is much lighter than a period in both flow and color.
>>MORE: Is It Implantation Bleeding or Just My Period? 14 DPO
The textbook luteal phase, based around a 28-day cycle, is 14 days long. So at 14 DPO, you’ve reached the end of the typical two-week wait! It’s possible to get a positive pregnancy test around 14 DPO.
Of course, this isn’t an exact science: the timing of when a test can come back positive all depends on when you conceived and your body. In fact, your luteal phase can be anywhere from
11 to 17 days and still be considered normal.
Just like your cycle is unique to you, your timeline for taking a pregnancy test may vary from the two-week, 14 DPO wait.
DPO: When should I take a pregnancy test?
Waiting until you’ve missed your period is a good rule of thumb for when to take a pregnancy test.
If you can’t wait any longer, you can try testing the same day or the day after a missed period. For some people, this will be around 14 DPO. For others, it might be a little longer.
If more time passes for you before a potential missed period, it doesn’t mean there’s anything wrong with you—you might just have to be more patient! Try adapting your “two-week wait” to your cycle timing.
Regardless of your cycle regularity, pregnancy test results will only get more accurate if you can manage waiting a bit longer. In fact, testing too early can result in false negatives. Holding off to test leaves the developing placenta more time to build HCG up to detectable levels. If you can, try waiting until a week after your missed period, then take a pregnancy test.