Medieval ideas about birth control were more varied and advanced than you might think. Also, some were just bonkers. I’ve got some highlights for you. If things get crazier with birth control regulations in the U.S., you could go Medieval.
Miniature of the birth of St Edmund, from Lydgate's Lives of Saints Edmund and Fremund, England, 1434–1439: Harley MS 2278, f. 13v
Plan B
If a woman suspected she was pregnant and didn’t want to be, she had some options. Some herbs known to medieval women as contraceptives are, according to Philippa Ogden, a scholar of the history of medicine writing for The Collector:
"...to this day...recommended as avoided by pregnant women due to their potency and potential as a fertility inhibitor. These included ingredients such as parsley, Queen Anne’s lace and pennyroyal. Other herbs and spices commonly used included arum, opium, artemisia, pepper, licorice, and peony which were mixed with varying levels of complexity and incorporated methods such as straining and steeping…”
Many of these herbs were said to "stimulate menstruation." They were less likely, say some scholars, to be cast as abortifacients, but that potential outcome wasn't a secret, according to historian John Riddle.
Prevention
Many medical manuals of the time offered up prescriptions for contraception.
"The most common involved taking a vaginal suppository – it would be an oil which could have ingredients such as cabbage flowers, pepper, juice of peppermint, leaves of pennyroyal or dill. One ninth-century physician explains that the best type of contraceptive was “oil, any kind of oil,” as it would slow the movement of sperm." (From Birth Control and Abortion in the Middle Ages, in Medievalists)
Magic
There were, of course, other options. From WebMD's They Put What Where? History of Birth Control:
"...some people wore amulets made of mule’s earwax, weasel’s testicles, and a bone taken from the right side of a black cat."
I don’t know which I love more. Or which would be harder to collect.
Want to learn more?
Here are some excellent sources:
This Scientific American piece on the surprising nuances around the discussion of contraception and abortion in the Middle Ages.
This round up of ideas about contraception includes Medieval women from the Middle East, in Medievalists.
This chapter in The Handbook of Medieval Sexuality, again, by top scholar in his field, John Riddle, covers it all.