This study from the Guttmacher, says:  

Half of respondents had experienced at least one unintended pregnancy. Respondents described three categories of pleasure related to pregnancy ambivalence: active eroticization of risk, in which pregnancy fantasies heightened the charge of the sexual encounter; passive romanticization of pregnancy, in which people neither actively sought nor prevented conception; and an escapist pleasure in imagining that a pregnancy would sweep one away from hardship. All three categories were associated with misuse or nonuse of coitus-dependent methods.

Now I have not read the Guttmacher study in full. But my translation on the “scientificese” above is this: Pregnancy is linked–strongly–to sex and sometimes women get pregnant the result of having sex. Furthermore, oftentimes unintended pregnancies are not unintended at all.

You know, I don’t like the idea that everything we do, including pregnancy, ought to be fully and completely planned. All it nurtures is a sense of failure if you can’t get pregnant the very moment you so desire, and a sense of failure if you get pregnant when you did not so desire. (If life is aaaaaalllll about planning, I might add that I’m way off track as per the official Andrea Mrozek 1995 high school graduation power point. See graph four, slide 15 for more information…)