Couple to Couple League is dedicated to promote and teach fertility awareness (natural family planning) to married and engaged couples for over 50 years.  

Liga de Pareja a Pareja is the branch of CCL focusing on Spanish Speaking Couples.  

Fertility Science Institute is a method-neutral outreach and supports women and men through a lifetime of fertility.

For more than 50 years, thousands of couples have learned NFP with CCL and LPP and trusted  our algorithms to help them track and interpret their cycles to determine peak fertility. CycleProGo was the app used by our students for the last ten years. It’s trusted and has a proven success rate for over 10,000 users. 

We are using that same highly effective formula and algorithm behind PeakDay.  

Couple to Couple League now uses the PeakDay app in CCL and LLP classes to learn the Sympto-Thermal method of NFP.