kegg measures electrolyte levels in the cervical fluid. These electrolytes fluctuate in response to hormones in the body – even from cycle to cycle – and are unique to every woman. kegg’s algorithms assess the patterns of your daily test results over time, rather than absolute daily values, to recognize and predict your fertile window. Your prediction will be labeled as ‘’Low’’, ‘’Possible’’ or ‘’Likely’’ and they will vary during the cycle.
Each woman has a unique kegg trend. In fact, your trend often varies from cycle to cycle as numerous factors influence your readings. In general, however, as estrogen rises while the body prepares to ovulate, kegg readings descend, on the y-axis. Typically we describe the fertile window as a “valley”, as there appear to be descending readings followed by a rise. After ovulation, the rising progesterone causes a shift in electrolytes resulting in this rise in kegg readings. Below we explore variations of normal fertile window trends.
This chart features a stair-step progression down throughout the follicular phase (before ovulation). These fluctuations which occur both before and after ovulation are typical. The predicted green fertile window captures the valley shape as there is a downward trend followed by the rise on cycle day 21. Note: it is very typical to have fluctuations in readings even within the fertile window (as observed with the slight elevation in reading on cycle day 19 followed by another descent on cycle day 20. kegg is able to capture this overall downward trend despite day-to-day variations.
This chart also features declining values after ovulation. kegg readings do not need to remain elevated post ovulation (unlike temperatures) and declining kegg values after ovulation do not indicate a problem nor declining progesterone.
In this chart, the valley depicted in the green fertile window is very slight. As you can see there is a downward trend beginning with the first reading of the cycle. The fertile window, the beginning of cycle day 12, captures a continued descent through cycle day 15 followed by a slight rise on cycle day 16. This valley, although small, is very typical and does not indicate a problem. kegg is able to capture and detect even these slight variations.
This chart features a deep descent into the fertile window. In contrast to the previous chart, some cycles will have more significant declining kegg readings as they approach the fertile window and in the fertile window. This is again a common trend and does not indicate a problem. Notice that not all of the readings descend, as is observed on cycle day 9 and 11. The overall trend is downward and these day-to-day fluctuations are normal.
Please consult our blog kegg chart 101 for further examples of kegg charts with explanations.