Preparing for catastrophic or short range survival is extremely personal and most of us keep it tight to our chest. I think PowderKeg says it best – Invisible and then Nuttus who knows that not all of us are the same skill or wherewithal stage, yet as a TEAM we shore up each others weaknesses, learn off each others strengths and it is a continual building process going forward.
However, a few unintentional similarities to the Quiverfull movement doesn't mean that preppers can't still care about safe sex. Hunting, canning, and digging your own latrines does nothing to make the threat of an STD less real. After all, gonorrhea and genital warts are going to be a whole lot harder to treat without reliable access to medical care. And there must be at least a few survivalists out there rational enough not to want to endure the horrors of premodern pregnancy and birth unless absolutely necessary.
To me, the best option is to store emergency food. How much? If you have none, store enough for a few days. If you have enough for a few days, get enough for a week. How much you store depends on what time frame you think you're at risk for having to be completely independent. The early settlers of the southwest liked to store enough food for a whole year and still do to this day!