As much time as most women spend trying to keep from getting pregnant throughout their lives, it sometimes seems that for any woman who is sexually active, pregnancy is the default condition.
Pregnancy sneaks up on millions of women every month: pregnancy has been known to occur during one’s period, while still nursing an infant, when a partner has had a vasectomy, and when women are on the Pill. Hormones, sponges, creams, foams and various latex and non-latex products have been pressed into use by women who aren’t at a stage in life where they want children. It’s only when we start wanting to have children that we learn that pregnancy sometimes takes as much planning as childlessness did before.

It may be that the hectic nature of daily life has changed considerably from the time when, eons ago, all you needed was enough to eat and enough shelter to keep alive.

In fact, the nature of nature is to make us as fertile as possible under a wide variety of circumstances. But our bodies are still trying to adapt to the environment we’ve built, where things like jet lag, hot tubs and plain old fatigue can affect whether we can become pregnant. The human body, while amazingly adaptable, is only willing to go so far: getting pregnant is often a matter of helping things along by working in a planful way to bring ovulation, active sperm, and a welcoming environment conducive to implantation together at the same time.