Students who are trained to "chart" their cycles can learn when they're fertile - and when they're not. They can use this information to postpone pregnancy - or plan pregnancy. They can also use this information to monitor their reproductive health - when something changes on their chart they will either be able to explain it (high stress levels that cycle - loss of sleep - etc), or they will know that it's time to see a doctor.
Keeping a record of your fertility is empowering! The Pill (and any other birth control method that relies on hormones) carries risks - there are potentially life-threatening side effects with any artificial method of birth control. Natural Family Planning is safe - there are no side effects - and it's as effective as anything else on the market when there is good instruction and the couple follows the guidelines they've been taught.
SO - do you want to have to buy a drug that you will take when you're not sick - that can make you sick (now or later) - or do you want to know your body? !