Fertility Awareness methods do not work in conjunction with hormonal birth control. The Art of NFP (edition in use in 2004) had instructions for going off hormonal birth control and none for going on to it. They were hyper conservative, too. For up to 6 months a couple going off the pill could only have sex a few days…

“typical use efficacy of 93 percent” means that 7 out of 100 couples who use this app will achieve pregnancy even if they are trying to avoid it. There are more reliable forms of fertility awareness available, but they are all dependent on the user providing reliable data and using it more conservatively (usually…