1. In Cleopatra's time, women used crocodile dung, honey and sodium carbonate as spermicide.
2. The ancient Egyptians also worried about getting knocked up in the afterlife.
3. In the 17th century, French women used sponges soaked in brandy to fight sperm.
4. Casanova, the 18th-century Italian ladies' man, put lemon halves over the cervixes of women he bedded.
5. In the 19th century, "female pills" promised to spur menstruation when a woman's period was late.
6. Douching syringes and "irrigators" were other options available at the time.
7. 17th- and 18th-century African and Native American women were early innovators of natural family planning.
8. Today, of course, there's an app for that.
9. The Pill was approved by the FDA for contraception in 1960.
10. It's now the most popular method of contraception among American women.
11. Condoms are big business, with global sales expected to reach 44 billion by 2020.
12. Condoms are the only form of birth control that protects against sexually transmitted infections (STIs).
13. Plan B, one of the most widely available brands of emergency contraception, doesn't work as well for women over 165 pounds.
14. The long-lasting IUD is way more popular abroad than it is the U.S.
15. However, more American women have been choosing IUDs in recent years.
17. Japan didn't legalize the Pill until 1999.
18. Birth control pills are available over the counter in several countries, including India, Ukraine, Guatemala and China.
19. In some countries where the Pill is available, it's illegal to advertise it.
20. Around 200 million women in developing countries want to avoid pregnancy but aren't using contraception, the World Health Organization says.
21. Lack of access to effective birth control is part of the problem.
22. Contraception saves children's lives.
23. It also protects women's health.
24. Human trials are slated to start in the U.S. next year for Vasalgel, a new birth control method for men that blocks sperm from leaving the vas deferens.
25. You can explore birth control methods to find one that works for you over at Bedsider.
26. So go on, celebrate World Contraception Day!
An earlier version of this post used the terms "natural family planning" and "the rhythm method" interchangeably. The rhythm method is one of several natural family planning methods that vary in effectiveness. Items 7 and 8 have been updated for clarity.