How do I find my implantation window?

Written by:, PhD, Founder and Inventor of the Proov test — the first and only FDA-cleared test to confirm successful ovulation at home.

If you’re trying to conceive, you may have heard a lot about ovulation, the importance of timing intercourse around ovulation, and finding the fertile window. This time in your cycle gets a lot of attention, and rightfully so! In order to conceive, you have to ovulate, and have sperm around to fertilize the egg. 

There’s another time in your cycle that’s critical for getting pregnant, though, and this one gets less attention – that’s the implantation window. We’re here to shine some light on the implantation window and teach you what it is, why it’s so important, and how you can find it. 

how do I find my implantation window

There's another time in your cycle that's critical for getting pregnant: the implantation window. 

What is the implantation window? 

After an egg is fertilized, it travels down the fallopian tube into the uterus, where it implants in the lining (the endometrium). Since it takes the fertilized egg a few days to get there, this isn’t directly after ovulation – in fact, it’s about 7-10 days later! For this reason, the 7-10 day time period following ovulation is termed “the implantation window.” 

During the implantation window, progesterone is at work stabilizing the uterine lining and making sure the new embryo has somewhere to go. This is the time in the cycle when progesterone is highest, and really the only time that the uterine is receptive to the implantation of an embryo – i.e. when an embryo can “stick” to the uterus. 

Sufficient progesterone levels during the implantation window are crucial for the health of an early pregnancy, so this time is nearly as important as ovulation! In fact, studies show that up to 75% of pregnancy losses occur due to failed implantation. Additionally, low PdG (a metabolite of progesterone) is associated with a higher rate of early miscarriage. 

For this reason, not only finding but also testing progesterone throughout the implantation window is key for detecting problems with ovulation and increasing your chances of a healthy, successful pregnancy.

How do I find the implantation window? 

Now you know that the implantation window is 7-10 days after ovulation. So if you want to know when the implantation window is, a good first step is figuring out your approximate time of ovulation! 

Only a well-timed ultrasound can detect exactly when ovulation occurs, but what you can do is find your peak fertility and use that as a pretty close estimate. This is usually done by testing for the rise of luteinizing hormone, the hormone that triggers ovulation. Once you detect your LH surge, ovulation will follow 24-36 hours later. 

You can test your LH surge with at-home urinary hormone tests, including Proov Predict, or included in a more comprehensive testing kit like Proov Complete. These methods will help you estimate peak day and ovulation timing, and from there you can count out 7-10 days. 

If you’re using the Proov Insight App, it will do the work for you, and use your hormone levels or the peak day that you input to calculate when the implantation window is. 

how do I find my implantation window

LH testing with Proov Predict or Proov Complete will help you identify your peak day and estimate you ovulation day.

So I found my implantation window – now what? 

Now that you know what your implantation window is, there are a few different directions you may want to go. Since progesterone is so important for healthy implantation and early pregnancy, this is the time to test your progesterone levels to make sure you’re ovulating successfully and preparing for the best implantation possible. 

You can test progesterone with a laboratory blood draw, usually on cycle day 21 or 7 days after ovulation. While this will help you get a snapshot of your progesterone levels at the point of the blood draw, progesterone fluctuates both throughout the day and throughout the implantation window. 

An alternative is PdG testing, or urinary hormone tests that check levels of a progesterone metabolite that reflects the average progesterone levels from the previous day! Proov Confirm or Proov Complete and the Proov Insight App will direct you to test on days 7-10 after ovulation, giving you PdG data and an Ovulation Score reflective of the entire implantation window. 

how do I find my implantation window

You may also want to learn about ways to support implantation, and what the symptoms of implantation are. 

Finally, what comes after the implantation window? Well, once the embryo implants, it begins to produce the hormone hCG, which means it’s possible to start having a positive pregnancy test! While traditional pregnancy tests recommend waiting until at least the first day of a missed period, with Proov Check you can test up to five days before your period is expected. 

So next time you detect ovulation, and enter the two-week-wait, you have something to do in the meantime – find your implantation window! 

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