Look I love my son and he is the best thing that happened to my life. But I can never shake off the feeling that I was "trapped". I say this because the mother of my child expressly told me she was on contraception and I should not worry about her falling pregnant.
But I was extra-careful. Of course it was not just her duty to prevent an unplanned pregnancy and so I also used condoms. We were not dating. It was just a holiday fling so I wanted to be careful. It was holidays and she spent all her evenings during the fling over at my place. Some evenings I would be out of condoms, and you know not having condoms is unlikely to stop you from having intercourse. Coupled with the fact that she said she was on prevention, it was easy to justify having unprotected sex.
So imagine my surprise when about 2 months later I received a phone call from her and she told me she was pregnant. The first thing I did was to deny it was my child. I did so based on the fact. If she was on contraception when she was with me, she can't have been impregnated by me. Surely!
But she was.
Needless to say, it was my child and I had no choice but to step up. Even though I was not happy about the turn of events, as a man it was my responsibility to live with the consequences of my actions.
smartDAD is right - preventing a pregnancy and having safe sex is the responsibility of both the man and the woman. Don't take someone's word for it that they are on contraception - or are HIV-. You never really know and you don't want to stake your life it.