This is a very important subject and something men will need to be aware of too because modern contraception has always been hormonally dangerous for women and modern contraception for women and men may not always be readily available - so casual sex or sex without wanting to cause pregnancy or STD's will not be a common option. That may be difficult for many nowadays but something that has to be accepted and respected. Just because some might think 'life is short' or will perhaps be considerably shorter in possible future times, it's not short when living with consequences and people are going to have to consider their behaviour when convenience products are no longer convenient.
RubyTuesday has pointed out that women can only get pregnant at certain times, good point, however it has many exceptions. Lt Ripley and Nire Raida have brought up the most common one and that is menstrual displacement, i.e. when your cycle is affected and changes times or skips - this makes it even more inaccurate when watching your period for 'safe times' or relatively safe times.
There's also the point that many women suffer very painful, prolongued or heavy periods which in many cases are dihibilitating. Periods are usually seen as a 'women's issue' and it is brushed under the carpet with jokes, ignorance and scorn. It's not something to be ashamed of, it directly affects almost half the population and by follow on effects the rest. There needs to be more communication and sympathy between women and men on this subject especially in survival situations because most girls/women will come with menstrual cycles or reproductive issues, they can't be separated and there's no point ignoring it; men need to accept that and women who have consistent and 'easy' periods need to be more compassionate to those that don't because there is much revulsion and lack of solidarity in society over this. This should hopefully prevent time wasting and emotionally draining conflicts from arising in groups.
The next stages through pregnancy and childbirth for those who want that will be of utmost importance too and as aforementioned emergency childbirth and midwifery will be a good skill for many, not just a specialist area because the more people that share skills the better. Gestation is long and needs a lot of support, something that has been marginalised in society because of the view that 'women go through it all the time, it's no big deal' and any emphasis has moved along to the child at the end of that particular period rather than the mother. Well it is important and even though it's a mass occurrance it's still individual, more respect and appreciation are going to be needed .
The natural products in the thread are a good idea, including the toothpaste - putting artificial chemicals in your mouth with all the chemicals already in there and the fact that it is a living, thriving and changing environment is not logical or healthy. As for the sanitary products, many will have to adjust to the not as comfortable or convenient 'comes with wings, bells and frills' cotton, non bleached, non chlorinated, bio-degradable options - but ethical and healthy is more important than convenience. The same goes for men, because the responsibility cannot be one-sided.
We will also have to brush up on our botany - it would be helpful to start incorporating natural remedies and products into your lifestyles now and start replacing/reducing artificial chemical dependancy. Your body is a natural thing so that not only includes what you eat/drink but what you consume on the whole e.g. the products you use in/on your body and around your household, from cosmetics to clothes to detergents.
Much is common sense that has been overridden by advertising and information is readily available but for those who always like a reference guide handy
- this is a good database reference:
http://www.pfaf.org/index.php