The first few months of pregnancy — the first trimester — are marked by rapid changes for both you and your baby.
For you, first trimester physical changes might include breast tenderness, fatigue and nausea. Your emotions might range from excitement to anxiety. For your baby, the first trimester is a time of rapid growth and development. Your baby's brain, spinal cord and other organs begin to form, and your baby's heart begins to beat. Your baby's fingers and toes even begin to take shape.
If you're in your first trimester, make an appointment with your health care provider to begin prenatal care. You'll find out what to expect during the first trimester and beyond. What you learn can help you take the best care of yourself and your baby.(From Mayo Clinic)