Contraceptives were well established even before the Church was founded. Theophratus wrote about the use of silphium during the 3rd or 4th century BC. The use of cotton as vaginal sponge was used throughout the ancient world. There were also a large number of abortifacients used in ancient times. Artificial birth control is not something that just developed in the last 150 years.
Many believe Saint Paul writes about birth control in Galatians 5:19-21
19 - Now the works of the flesh are obvious: immorality, impurity, licentiousness,
20 - idolatry,
sorcery, hatreds, rivalry, jealousy, outbursts of fury, acts of selfishness, dissensions, factions,
21 - occasions of envy,
%between% drinking bouts, orgies, and the like. I warn you, as I warned you before, that those who do such things will not inherit the kingdom of God.
In the above the original word for sorcery is pharmakeia (i.e. the mixing of potions for secret purposes). Given the context it is reasonable to accept that pharmakeia was not talking about medication, but rather potions related to sins of the flesh.