Usually the nausea begins just after a menstrual period has been
missed, and ceases about the third month or a little later.

But morning sickness is never counted an indication of pregnancy
unless taken in conjunction with other symptoms, for individuals who
are not pregnant may also suffer from nausea in the morning. On the
other hand, a number of prospective mothers escape morning sickness
altogether, and a few experience nausea at other times of day.

_Disturbances in Urination_.--It is not an uncommon belief that
some characteristic change occurs in the urine shortly after
conception. But this is not true; at least no change is revealed by
any method of analysis known at present. Yet there are symptoms
associated with the passage of the urine which appear very promptly
and prevail for several weeks. Chief among these is the desire to
empty the bladder frequently; some patients also have difficulty in
urination, and a few experience discomfort with it. All the bladder
symptoms gradually disappear about the fourth month, but become
prominent again toward the end of pregnancy.

Since the inclination to empty the bladder more often than usual may
be due merely to nervousness or to many other conditions, this
symptom taken alone cannot be regarded as a definite sign of
pregnancy. Indeed, it is mentioned, not because of its importance,
but to point out that it is in no way connected with the kidneys, as
patients are sometimes led to believe. It is a direct and natural
result of pregnancy. Since the womb enlarges and tilts forward at a
more acute angle than formerly, it presses against the bladder,
giving the same sensation as when the bladder is distended with
urine.