"Abortive agents" were well known enough that Hippocratese included a warning against their use in the original Hippocratic Oath. So yeah, they've been around for quite a while.
Physically, I've read more than a few literary references to "find an old woman with a crooked stick", which is more than gruesome enough an image. We will explore that direction no more.
Alchemically/herbally, an infusion made from the herb Pennyroyal was an effective abortive agent, though it made the woman very ill for a while.
A lavage of extremely salty water applied to the, erm, "internals" was known to work as well. Another direction we will not delve into again, I expect.
Many version of propylactics were used throughout the ages. Sheaths made of fish or eel skin, lambskin etc were used with various degrees of effectiveness.
The military used to believe that adding saltpeter to the soldier's food would curb their "appetites" in that direction. It interfered with the mechanical function to some degree, but did not in fact do anything to reduce desires.
Over all, the best birth control in game is to have the characters keep their pants on. Been known to work pretty well in the real world too.