[ealgeone]

First of all the two “methods” are one and the same. And NFP is not artificial.

Catholic natural family planning is a way to avoid or achieve pregnancy based on awareness of a woman’s fertility. This is not the “rhythm method!”

http://www.beginningcatholic.com/catholic-natural-family-planning

Apparently you're not well informed on this topic either.

[ebb tide]

Both you and source are wrong.

And I highly doubt you'll ever answer my question.