PERIMON - Free cycle calendar

What is PERIMON?
PERIMON is a cycle calendar which gives you insight into your cycle. PERIMON is a contraception and conceiving aid for women from 18 to 45 years of age. It is easy to use and reliably renders its service since 1996. You simply enter your menstruation date once a month and check your cervical mucus if required
What is the difference between PERIMON and other menstrual calendars?
To optimise its forecasts PERIMON calculates - in contrast to many other products - your actual cycle length and ovulation date. Furthermore PERIMON was designed with the focal point on safety. Whereas many other calendars only display statistical fertility values or designate too many days as infertile by default, PERIMON's fertility analysis is based upon the data of your individual cycle and includes a wide safety reserve for cycle irregularities
Is birth control with PERIMON safe?
You'd better ask "Is PERIMON safe enough for my needs", because contraception can always fail. PERIMON operates very cautious: If you use PERIMON only with the rhythm method, we estimate the Pearl index by comparision to 3.8 or better (a good safety). If you additionally examine your mucus or cervix on the days in question - which is easy to do - safety will increase up to 1.0. Whenever there is a case of doubt PERIMON goes for safety
What is the disadvantage of PERIMON?
PERIMON only designates at most 10.5 days per cycle as infertile and needs ca. 3-8 cycles before it starts with prediction. These are the limitations of the rhythm method that can be extended by you by combining PERIMON e.g. with the cervical mucus observation (which we recommend). AN ONLINE version of perimon can be found at WWW.PERIMON.COM