I wore the condom and the precum was also while I was wearing it,, and then I ejaculated later while masturbating.. the precum was while I was wearing the condom.. still my wife's periods are late by 4 days and there are no symptoms of getting it, what could be the reason?? Can some help

You are not really clear, about it, did you only have sex with your wife that one time all month ?

But condoms fail about 10 percent of the time. So if that is the only protection you were using and you had sex, of course there can be pregnancy

I did chk the condom before and after having sex.. and yes it was only this once in the month.. cause then she went to her mothers place to stay