*Situação vista em obras de ficção,onde a mulher tenta engravidar para obter alguma vantagem,tendo dito que estava se prevenindo(pílula).
Um trecho em inglês do Yahoo:
Sadly, there probably arent many signs of psycho-ness early on. We women are pretty sly and know how to conceal things. You're best bet is to ALWAYS use a condom, the pregnancy trick is the oldest in the book! No matter what she tells you, always use protection. My poor brother got duped by the old "its ok, I'm on the pill" line, even though I told him since he was a teenager to always wear a condom.
Other than that, be sure to date someone for a long time and live with them if possible before marriage. Good luck!