Fertility period calculator

A fertility period calculator comprising:

• a flat rigid planar, thin, hand-sized member having an annular aperture centrally disposed therethrough, a plurality of numerical indicia equally surrounding a perimeter of said annular aperture having the numerals 1 through 31 representing the days of the month;
• a circular disk having an annular lip sized and rotatably mounted in said annular aperture portion of said flat member, said circular disk including a central upper handles means having an alignment indicia disposed thereon, and a pair of identifying probes, spaced apart, extending radially beyond a circumference of said disk, the space between the probes sized to encompass only one numeral at a time of the total numerals surrounding the perimeter of said planar member aperture, said probes highlighting the actual day of the month, said probes aligned to move relative to said member indicia;
• said disk including numerical indicia substantially relating to the total number of days within a single average menstrual cycle from 22 to 39 displayed around a predetermined portion of said disk;
• and
• a ring rotatably mounted on top of and engaged with said disk, said ring including a circumferential portion extending radially inward that covers the numerical indicia displayed around said disk relating to the menstrual cycle total days and an observation window, said window sized to view one number of the menstrual cycle total days, said ring having an enlarged circumferential arc area extending radially outward over a segment of the numerical indicia surrounding said annular aperture, thereby covering particular days of the month when conception is most likely to occur.