I think it's important to note that time to suppression is not the same in all males and can take 8 to 12 weeks to reach a reasonably "safe" level of suppression for male birth control. It can also occur within 3 to 4 weeks.
How far were any of you into your cycle when you got your wife, g/f pregnant?
I (and my friend) have been using test as my primary form of b/c for the last 2 and a half years very successfully. The key is a little (ok, a lot) of research up front. I went through about 100 studies, and only weighed 17 of them as really being valid, before I decided how to implement it.
-B