Before C0nd0ms and pills were invented, people were still concerned with preventing pregnancy and family management so that the family does not grow exponentially. But you would be disgusted to learn the things they used to prevent it. As a matter of fact, c0nd0ms were inspired from one of such a substances that were used extensively by men. Even pills for contraception are inspired from them.
If you are shy to go to the medical store to buy c0nd0m or pill before you lay down with your partner on the bed and do the most passionate act, you may just give the following substances a try and hope they would work. Some of these substances were highly poisonous while others are extremely hilarious and you have to use your wild imagination to understand how they were used.