**Identification and prediction of the fertile window with a new web based medical device using a vaginal biosensor for measuring the circadian and circamensual core body temperature. Regidor PA., Kaczmarczyk M., Schiweck E., Goeckenjan M, Alexander H. Gynecological Endocrinology 2017. DOI:10.1080/095135910.2017.1390737. see the publication.
*** The daily conception probability is usually given from the second cycle onwards, since a learning cycle with ovulation is required for this.
**** The ovulation prognosis is usually made for the fourth cycle, since three cycles with ovulation are required as learning cycles. If the ovulation day varies by more than 8 days in the successive cycles, no reliable forecast can be given. This does not affect the calculation of the daily conception probability, which is why OvulaRing can make precise statements even with irregular cycles.