re: Effectiveness of NFP method.
I know a lot of people using it, and I've only seen an "oops" happen when the couple takes a very knowing risk. So you do have to have some will power if its important to you not to get pregnant. Also the 3 months practice rule (especially when coming off hormones) is absolutely vital before you start to rely on it. I've always had perfectly normal cm and temps when coming off the pill, but the majority of women I know have very weird cycles at first. So that can take some patience.