Re the feminine products:

I'm a guy, but I've studied up on this. Birth control is a big dose of female hormones in order to prevent normal ovulation. When they stop taking this, the body attempts to return to a regular menstrual cycle, but in the transition there's a major flow at first. Very heavy bleeding will happen that might cause fear since it's unexpected from abnormally low flow from taking the birth control pills.

Also, when many women live together, they tend to synchronize their cycle too.

OK, let's say that you're bugging out during this process. This could be a serious issue with tons of hiking. You have to consider this carefully.

I've heard that these products could be used for a wound dressing too, and that may be very important. It follows due to it's normal use to staunch flow.

Under stress people tend to either have more sex or less depending upon the way they cope with danger. A lack of birth control and potential pregnancy under less than ideal conditions means that understanding basic gynecological issues like urinary infections, early pregnancy issues, unusual spotting, breech births, etc might occur and be dealt with no backup.

Under stress and malnutrition, a woman may stop ovulating regularly based upon Nature's way of preventing pregnancy. This can cause confusion with folks unsure if they've missed a period.

There are three books I recommend that are free from the Hesperian Foundation: When there is no doctor, When there is no dentist, and A book for midwives. They can downloaded for free and would be very important to have.
[link to hesperian.org]
These are made for conditions where there is a lack of medical equipment.