Exclusive breastfeeding as a form of family planning should be under natural method in my opinion.
Of course, it is stated under natural family planning. I only discussed it among the three widely adopted family planning methods.
Also, the effectiveness of this method varies with individuals and it goes beyond the first six months. Some women do not menstruate at all throughout the period they are breastfeeding and as such, don't get pregnant.
This is a fact no one can deny.
I appreciate your sincere contribution!