In Biblical times there were methods of contraception practiced. For example Aristotle and others in Biblical times, recommended that woman use oil, honey or cedar resin to prevent sperm from ‘penetration of sperms into the uterus cavity’. (Source, P165).
From Biblical history the church seems to have generally used the story of Onan (Gen 38:9) and the general principles of ‘multiplying and filling the earth’ as reasons to oppose birth control. This can be understood culturally, because until recently many wanted large families (could in a sense afford to) and it was almost even seen as a sign of God’s blessing and status to have a large family.
However when we come to the Bible, considering the fact various methods of contraception were used in ancient Greece and Rome, the bare facts are that the Bible simply does not engage with the subject. Also, having read many thousands of pages from the Reformers in the 15 – 17th Century I have never comes across the subject either.
Just because the Bible does not touch upon a subject does not mean it positively allows it though. The Bible dos not complain about the Roman Amphitheatre, but it can be understood that killing men in a theatre as a form of entertainment is not Biblically supported.
I think when we find subjects that the Bible is not interested in, then each person is responsible to make up their own mind using Biblical principles.
In my own mind I would never have my conscience disturbed about temporary or permanent contraception. It may even be the ‘moral’ thing to do depending on the situation. For many Christians this subject simply is not an issue. Until I saw this question I do not think in the last 30 years of studying the Bible I have actually thought abut the subject.
Having said this, this might be like the ‘eating meats’ sacrificed to idols issue. In other words some one else might have their conscience bothered by such things so for them it becomes a sin and we must not use our liberty is such a way as to disturb our brother. So we should allow other’s to have their views on the subject and not be dogmatic about our personal and more private choices and beliefs.