Catholics, and non-Catholics, often have extreme views about both natural family planning, and fertility awareness for contraception. It is either claimed as a panacea - the only contraception anyone will ever need - or dismissed out of hand.
My hero promoted a more balanced view. His name was Professor John Marshall and he's my hero for the work he did in his spare time as a natural family planning (NFP)* teacher for 40 years from the 1950s to the 1990s, and for the book he wrote about this work. [He also did amazing work on stroke in his day job as a neurologist, but that's another story.]
Strictly speaking, natural family planning is the Catholic cousin (or grandmother?) of fertility awareness based