Cell phone apps that track a woman's body temperature over time are making natural contraception feel more like a 21st century option.

For women and couples tired of the the hormonal changes brought on by the Pill, natural contraception offers a high degree of accuracy—but only if used consistently, say health experts.

A thermometer called Daysy (complete with accompanying iPhone app) claims to have 99.3 percent accuracy, which is about the same as the birth control. 

It relies on the basal body-temperature method of family planning, based on the fact that women’s bodies are a few degrees hotter just after ovulation.

While past generations wanting to use natural birth control methods would have to track temperature records by hand, the new app creates a digital "cycle forecast" and "temperature curve."

Although the birth control pill is a symbol of the women's rights movement which emerged during the sixties, more recent generations are less satisfied with taking synthetic hormones—especially when there is a more natural option. 

In a recent study, the Centers for Disease Control found that sixty three percent of the 12,000 women surveyed stopped taking the Pill because of its side effects. The study also found that the rate of "pulling out" as a birth control method has increased to sixty percent, up from twenty-five percent in 1982.

Natural birth control forms part of a trend in which the rising generation harkens back to the styles of their grandparents, from wearing suspenders and pickling food, to growing bushy beards and tracking their body temperatures in a notebook—or iPhone app, as the case may be.

Jessica Valenti, author of the feminist blog "Feministing" and author of "Why Have Kids?", discusses her controversial decision to get married, which also went against the grain of popular feminist politics at the time:

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