Pregnancy Tracker

Pregnancy is dated from the first day of your last menstrual period (LMP), even though conception typically occurs about two weeks later. This means that when you are described as being 4 weeks pregnant, the embryo is roughly 2 weeks old. A full-term pregnancy lasts about 40 weeks, or 280 days from the LMP. These 40 weeks are divided into three trimesters: the first trimester (weeks 1 through 12), the second trimester (weeks 13 through 27), and the third trimester (weeks 28 through 40).

During the first trimester, all of the baby's major organs and systems begin to form. By the end of week 12, the baby is about 2 to 3 inches long and has developed recognizable features. The second trimester is often called the most comfortable period of pregnancy, as early symptoms like nausea often subside while the baby grows rapidly and begins to move. The anatomy scan, typically performed between 18 and 22 weeks, checks for structural development. In the third trimester, the baby gains significant weight, the lungs mature, and the body prepares for delivery.

This tracker uses ACOG pregnancy dating standards and provides general developmental milestones based on average fetal growth data. Every pregnancy progresses differently, and your healthcare provider will monitor your baby's specific growth through ultrasounds and prenatal visits. This tool is for educational and planning purposes and does not replace prenatal care from your OB-GYN or midwife.