What better way to not have to worry about becoming pregnant than to not have sex? It's 100 foolproof (well, to the extent of your primitive desires). No need to worry about whether you took your pill or having to put stuff where it doesn't belong? Practice abstinence and forget your pregnancy worries!
I think if your going to have intercourse with someone you better be prepared for pregnancy.
It amazes me how relaxed most people are about birth control. To me having a child is a big deal and I wouldn't trust anything other than abstinence for birth control. There is no other practical and full proof method.