Swollen, tender, or sore breasts are first physical sign of pregnancy because the breasts are undergoing changes to prepare for breastfeeding. This is caused due to increased production of the Estrogen and progesterone.
Morning sickness can hit you any time in the day, or even all day. It happens because of the increased level of hormones in your body during pregnancy. These hormones affect the digestive system, causing nausea, vomiting, constipation and acidity. Estrogen may cause sensitivity to odours.
Missing your period also makes you suspect pregnancy. Only a pregnancy test followed by a pelvic exam, can tell you positively whether you are pregnant. Once your health care provider rules out pregnancy as the cause of your late or missed periods, the next step is usually to rule in or out several other possible explanations for absence of menstruation or amenorrhea.
Cramping which is similar to menstrual cramps occurs very early during pregnancy and happens when the uterus begins to expand to create space for the embryo to develop into a fetus.