Pregnancy is the period time during which a baby develops inside your uterus. It usually lasts about 40 weeks starting from the first day of your last menstrual period. These are categorized by 40 weeks into three segments, called trimesters. The first trimester lasts about 13 weeks. During the first two weeks, you are not pregnant because of the way your due date is engaged, but your body is preparing for pregnancy during the second week. An egg is free from your ovary in a process called ovulation.

 

Around the end of the second week, the baby becomes pregnant in a process called conception or fertilization. During the conception of genetic material, the mother and father combine to form a unique genetic code of instantly determining sex. Hair color, eyes color, and hundreds of other characteristics, This new single cell is called a zygote. The beginning of a new human being during the third-week zygote divides to form a hollow ball of cells called a blastocyst. The cells of the blastocyst begin to arrange themselves into two groups, the inner group will develop into your baby, and the outer group will form tissues to nourish and protect its during week four, the blastocyst moves into the uterus, where it hatches out of its outer layer once freed from this outer layer.

The blastocyst can embed itself in the thickened lining of the wall of the uterus in a process called implantation weeks five to ten are referred to as the embryonic period, all of the major organs start to grow, such as the brain and spinal cord and heart the heart begins to beat, during this period structures called the placenta and umbilical cord begin providing life support for the embryo. They bring nutrients and oxygen from the mother to the embryo's bones, and muscles start to grow beneath thin transparent skin toward the end of the embryonic period. The fetus begins to look more human at the end of week 10. it's called a fetus during the next few weeks and is about one and a quarter inches long from head to rump. The arms and legs grow longer and start to move fingers and toes, and the baby's face becomes well-formed by the end of the first trimester. The baby is almost three inches long. Your body experiences many changes during the first trimester due to changing levels of chemicals called hormones circulating through your body. The most common first sign of pregnancy is that your menstrual periods have stopped. You may have other symptoms called morning sickness that can occur at any time of day, swollen breasts, and mood swings.

Constipation of weight loss or weight gain craving, or disliking certain foods and feeling more tired than usual you may have only a few of these symptoms or none at all if you have any questions about how your baby is developing or concerns about how you're feeling talk to your health care provider.