Thank you. There is a lot of misinformation going around on the internet.
You have the right idea, but the wrong science. “Ovulation occurs over a period of about 15 minutes and even when more than one ovum is released, as in a twin pregnancy, the multiple ovulations occur very close together in time.”
woomb.org/bom/science/physiology.html This is why NFP works. Genuine method errors are rare, but they do happen. Most of the time when a couple has an unexpected pregnancy, it is due to human error. But since 100% of couples who use it are human, this can be expected.
Oh, if you haven’t been to
woomb.org, it is THE site for the science of NFP. The Billings Method is the foundation of all modern forms of NFP and was discovered by two married Catholic doctors in Australia who promote it in a non-sectarian way.
Their more “user friendly” site
www.thebillingsovulationmethod.com is a great introduction to their method with full instructions. In my opinion it is the BEST NFP site on the internet and a link that you should forward to ANYONE who is wondering about Church teaching, any couple who is interested in an alternative to contraception, or just any woman who wants to know more about her body.