mal_ cases, the ovum only passes into the womb once in
every twenty-eight days; and, as a rule, it only remains in the womb
for about half that period of time, that is, for about 14 or 15 days
in each month. And so, since the menstrual flow ceases after about
five days from its beginning, in about ten days _after_ its stopping,
the ovum will have passed out of the womb, and hence that organ
contains nothing that is impregnable. Under these conditions, semen
may be deposited in the womb, without danger of impregnation. This is
a simple proposition, and easy to understand if once known.

However, it must be said that these _generally_ common conditions _do
not always obtain_--that is, they are _not_ true in the case of _all_
women. There are women who will conceive at _any_ time in the month,
if they are given a chance to do so. The physiological reason for such
possibility is said to be this: There are always ova in the ovaries,
in varying stages of development. Ordinarily, only once a month do any
of these pass down into the womb; but, in exceptional cases, sometimes
these ova are so partially held in the ovaries that, under the
excitement of coitus, and because all these parts dilate so much
during the act, an ovum may slip its moorings, under such conditions,
pass down into the uterus at an untimely season, meet the semen there,
and pregnancy result. Such are the facts _in some cases_.

How, then, can a husband and wife tell how it is, or will be, in
_their_ particular case?

The answer is that they can only tell by trying, and that should be
done as follows:

The _first_ sexual meeting of the bride and groom should _never_ take
place until at least _ten days after the ceasing of the menstrual flow
in the bride! This is a rule that should never be violated_ if the
parties wish to "_test out_" the real condition as to whether or not
the bride has any "free time." The chances are several to one that she
_has_ such leeway; but the fact can only be established by "proving
up" and this can _never_ be done if any _chances_ are taken. Put this
down as rule number one.

For this reason, it is well for the bride to fix the wedding day; and,
if possible, for her to locate it sometime during the probably immune
period. And the nearer she can bring this day to the _beginning_ of
such period of freedom from danger of pregnancy, the better. For, if
it should happen that the first coitus should take place only a
_day or two be