First Pregnancy trimester

During the first trimester of pregnancy, which lasts approximately fourteen weeks from the first day of your last menstrual period, your body is hard at work forming one of the most intricate and complex works of nature. By the end of your first official month of pregnancy (six weeks after your last menstrual period, but four weeks since conception), your developing child will have grown an astonishing 10,000 times in size.
The first trimester of pregnancy is marked by an invisible yet amazing transformation. And it happens quickly. Hormones trigger your body to begin nourishing the baby even before tests and a physical exam can confirm the pregnancy.
Knowing what physical and emotional changes to expect during the first trimester can help you face the months ahead with confidence.