Because your NFP should be evidence-based
When compared to monitoring cervical mucus only, use of eletronic fertility hormone monitor proved more effective as a family planning method.
The above studies are only a sample of research that has been conducted in regards to the Marquette Method of NFP. Research is ongoing, as the creators of the method continue their efforts to improve, broaden and test new protocols to incorporate other ways of monitoring fertility. Click here for a continued list of current research conducted by Dr. Richard Fehring, one of the lead developers of the Marquette Model of NFP. Here also is a list of all current NFP research compiled by the USCCB.