Does anyone have any information comparing fertility monitors to prevent conception?

I know that there are several types that are available in Europe that claim to be very reliable but have only been approved by the FDA for conceptive (not contraceptive) purposes in the US.

I am curious which is more reliable monitoring
Basal Body Temperature, LH & E3G, electrolyte levels?

I am currently breastfeeding and my periods have not returned. My husband and I are open to learning and practicing Fertility Awareness or Natural Family Planning methods, but would like to have monitors as a double check on fertile and infertile points of the cycle.

Any advice please!?!

Well, I don't believe in those things. I know that people say that's the only time you can get pregnant... but you can get pregnant on your period! It's God's will.

i think you cant really guarantee those things unless you are very regular and know your cycle.