Doing this can be either contraception or fertility treatment
Some days are more fertile than others, if you time sex during those times you are more likely to get pregnant; if you time abstinence during those days you are more likely to not get pregnant. So in truth, tracking cycles is both a contraception method and a fertility method, all in one!
1. This method is very old, and sanctioned by some organizations for religious reasons.
2. Beaded necklaces have been used in third world countries
3. Georgetown University has developed an easy way to track it, calling it their Standard Method.
4. There is now an app for that as well, and it's been tested. Natural Cycles became the first app approved by the FDA to prevent pregnancy. Natural Cycles claims they are “a natural method of contraception that is powered by a smart algorithm.” You have to tell it data, and it gives you the information you need to know. So it's good if you are faithful and consistent with the information tracking, or it may not be effective for contraception.
5. You can use a thermometer to track ovulation, and there are OPK kits to track the LH surge women get when they are ovulating, or even check for fertile mucus.
However, don't forget escape ovulations are possible any day of your cycle, so if you want the most effective treatments, there are other better methods! Contact your gyno to ask questions and find out which method might work best for you!