Once you find out that you're carrying a baby, the next question is often, "How long am I in my pregnancy?" There are ways you can estimate the length of time and your doctor has more accurate methods. Learn how to tell how far along you are by following these steps.
Make sure that you are really pregnant. If you believe you are carrying a baby because you have missed your period, it could be a false alarm. Use a home pregnancy test to confirm that you truly are a mother-to-be; don't waste your energy agonizing over the signs of pregnancy you read about online.
Count forward from the date of your first missed period up to the present. That will give you a rough idea of how many weeks you have been pregnant. You can narrow this down more closely by using a pregnancy calculator that considers the date and the usual length of your cycle. One such calculator is listed in the Resources section.
Pay attention to signs of movement from the baby. Normally you will be able to feel the fetus moving around distinctly between 14 and 18 weeks into the pregnancy. If you feel moving and kicking, you're probably at least 3 1/2 months along and possibly farther.
Visit your doctor for a physical examination. Through a combination of asking questions and performing a physical exam, your doctor should be able to make a close estimate of how long you have been pregnant. He will also be able to make recommendations for proper prenatal care to help keep the growing baby healthy.
Get an ultrasound examination. Because the ultrasound allows the doctor to actually see and measure the baby, she will be able to make a very accurate assessment of its age. Depending on how long you have been pregnant, she may also be able to determine its sex.