Kegg is a small, insertable fertility sensor that reads the electrolyte levels in your cervical mucus to identify your fertile window each cycle. You take a reading once a day, and the companion app translates that data into a chart showing when you’re most likely to conceive. Here’s how to get started and make sense of what the device tells you.
How Kegg Actually Works
Throughout your menstrual cycle, shifting hormone levels change the concentration of electrolytes like sodium, calcium, and potassium in your cervical mucus. Around ovulation, rising estrogen makes mucus wetter, stretchier, and more conductive. Kegg measures these changes using a technique called electrical impedance spectroscopy, essentially sending a tiny, imperceptible electrical signal between its sensors and measuring how easily current passes through the fluid.
The result is an impedance value that gets plotted on a graph in the app each day. When impedance drops, it means your mucus has become more fertile. When it climbs back up after ovulation, your fertile window has closed. This gives you a way to track mucus quality objectively, without relying solely on visual or tactile checks.
Taking Your Daily Reading
The process is straightforward. You insert the kegg sensor vaginally once per day, and the device takes its reading in about two minutes. Most users test at the same general time each day, though consistency matters more than picking a specific hour. The reading syncs automatically to the kegg app via Bluetooth, where it’s added to your cycle chart.
A few practical tips for accurate readings:
- Avoid testing right after intercourse or using lubricants, as these can alter the mucus composition the sensor is trying to measure.
- Stay consistent with timing. Testing at roughly the same point in your daily routine reduces noise in the data.
- Start early in your cycle. The more data points kegg has from the beginning of a cycle, the better it can identify the downward trend that signals fertility.
Reading the Chart: What the Valley Means
The most important pattern you’ll learn to recognize is called the “valley.” This is a visible dip in your impedance readings on the app’s graph, and it corresponds to your most fertile days, when cervical mucus is stretchy, slippery, and sperm-friendly. Timing intercourse or insemination during this valley gives you the best chance of conception.
The app also generates a predicted fertile window based on your cycle history. Think of this prediction as a forecast. The valley itself, once it appears in your real-time data, is the confirmation. If you see a downward trend in your readings roughly three weeks before your next expected period, that’s often a sign your fertile window is opening.
Dips That Don’t Mean Fertility
Not every dip in the chart signals ovulation. Many users notice a small valley shortly after their period ends. This is a normal fluctuation and doesn’t indicate fertility unless it falls within your predicted fertile window. Similarly, some users see bumps and dips during the luteal phase (the second half of the cycle, after ovulation). These are natural variations and do not mean a second fertile window has opened.
If your fertile valley forms later than predicted, it likely means ovulation was delayed that cycle. This is common and not a cause for concern on its own. In cycles where ovulation is significantly delayed or doesn’t occur at all, you may see multiple valleys as your body makes repeated attempts. Irregular patterns like these over several cycles are worth discussing with a healthcare provider, as they can sometimes point to conditions like PCOS or anovulation.
Using the App Beyond Impedance Data
Kegg’s app does more than display your impedance chart. You can optionally log additional biomarkers to build a more complete picture of your cycle. The app supports LH test results (from ovulation test strips), progesterone metabolite (PdG) test results, basal body temperature readings, cervical mucus observations, intercourse or insemination timing, and spotting. When you log BBT alongside your kegg data, you can view both trends simultaneously on the same chart.
This layering is useful because different methods confirm different things. Kegg’s impedance trend helps predict fertility before ovulation. BBT confirms ovulation after it’s already happened, through a sustained temperature rise. LH strips detect the hormone surge that triggers ovulation, typically 24 to 36 hours before the egg is released. Used together, these tools cross-reference each other and reduce the guesswork of any single method.
How Kegg Compares to Temperature Tracking
Basal body temperature is one of the oldest fertility awareness methods, but it has a fundamental limitation: it only tells you ovulation occurred after the fact. The temperature shift happens post-ovulation, which means by the time you see it, your most fertile days have already passed. This makes BBT useful for confirming ovulation patterns across cycles but less helpful for timing conception in real time.
Kegg’s impedance-based approach works in the opposite direction. Because cervical mucus changes before ovulation in response to rising estrogen, kegg can flag fertile days as they’re happening, giving you time to act. A study published in the National Library of Medicine confirmed that cervical mucus electrical impedance offers a reliable measurement for defining the fertile window based on hormone-associated electrolyte changes, positioning it as a practical alternative to temperature-based methods for real-time prediction.
Cleaning and Charging
After each use, rinse the sensor with warm water. You don’t need soap, boiling, or harsh chemicals. Pat it dry with a soft towel or let it air dry completely. This last part matters: the device needs to be fully dry before you place it back in its charging cradle. Moisture on the sensor or charging contacts can interfere with the connection.
The charging cradle keeps kegg topped up between uses. There’s no complex maintenance schedule. Just make the rinse-dry-cradle routine part of your day, and the device stays ready for the next reading.
Getting the Most From Your First Cycles
Kegg improves its predictions as it gathers more data from your body. Your first cycle will provide a baseline, but the algorithm learns your personal patterns over time. By the second or third cycle, the predicted fertile window becomes more tailored to your specific rhythm.
During those initial cycles, pay close attention to the raw impedance trend rather than relying exclusively on the predicted window. Look for the valley pattern yourself as you get familiar with how your chart behaves. If your cycles are irregular, expect the predictions to take a bit longer to calibrate. Logging additional data points like LH tests during these early cycles helps the app refine its forecast faster and gives you backup confirmation while you’re still learning to read your chart.