I have used it to achieve all 3 of my babes and also to avoid for all the yrs in between
I do feel that once you are familiar with your cycle that this is a reliable way to keep track of things. I have wonderful peace of mind and really enjoy using this method.
I would recommend using some back up for a few months until you are comfortable with what your body is up to. Wisdom and self control will definately have to come into play at times so be prepared.
If you truely want to avoid a pregnancy you MUST be attentive and always be willing to flex a bit.In other words, one month might look a little funny and you'll need to be on the safe side IYKWIM? Also if you prefer to not use any barrier methods ( like my DH and me) You'll have to be prepared to excersize some SERIOUS self control or get a little *creative*
OK I'm done now it's getting late and I think I'm getting a tad gitty.... Ta Ta for now!!!
Edited for grammer