The earliest signs and symptoms of pregnancy, such as those that occur within the first five weeks, aren't noticed or experienced by all women. By the fifth week of pregnancy a woman will have missed her period and she may have taken a pregnancy test and received positive results. Other symptoms and signs may or may not have occurred during these early weeks.
Sometime after the first or second week of pregnancy a woman's breasts may begin to swell slightly and feel tender to the touch. Women may find that during and after the fifth week of pregnancy the tenderness continues and the nipples may be very sensitive to even fabrics being against them. At some point in the pregnancy a woman's areolas will become darker. This can occur at any point but typically becomes noticeable between the fifth and 10th weeks of pregnancy. The woman may also notice an increased fullness in the breasts.
Fatigue can begin as early as the very first week of pregnancy. As the pregnancy continues this fatigue can intensify until the 18th week, when it will improve until the third trimester begins. Every woman and pregnancy is different so the onset of this strong pregnancy fatigue varies. Most women will experience it by at least the sixth or eighth week of pregnancy but many notice it sooner.
Morning sickness occurs sometime between the second and eighth week of pregnancy. This symptom of pregnancy includes nausea, vomiting, food aversions, food cravings and sensitivity to odors. Some women never vomit with morning sickness but feel nauseated frequently. Despite being called morning sickness, it can occur at any time of the day or night and may even last the entire time a woman is awake. This symptom usually improves by the end of the first trimester.
A low, dull backache is common in early pregnancy and may persist throughout the 40 weeks. Some women experience this only when the baby and womb are rather large but other women experience it right away due to the increase in the hormone relaxin. Relaxin increases during pregnancy to make the joints of the body flexible in preparation for labor. Women can change posture due to the loosening of the joints, which can cause a backache as well.