Pregnancy Week by Week
First Trimester: 1-14 Weeks
Second Trimester: 15 to 28 Weeks
Third Trimester: 29-40 Weeks
First, see how far along you are with our due date calculator. In each of the weeks pregnant segments you'll learn valuable tips about your baby's development and the changes that are occurring in your body. We'll answer some of the most common questions and cover many critical topics and symptoms related to each week and trimester of pregnancy.
All you have to do is click the week you are interested in learning more about! Feel free to read ahead or re-read sections any time you please. We want to make sure you get the most out of our pregnancy week by week section!
**Please note - Your Due Date is calculated from your last menstrual period which corresponds to the Pregnancy Week by Week articles.
Every pregnancy is unique, but in general, obstetricians and other healthcare providers calculate the length of pregnancy starting with the date of your last menstrual cycle. This is due to the fact, most women don’t know when they actually conceived. (Half of all pregnancies in the United States are unplanned and accidental.) However, women typically know the date of their last period.
After recognizing the early signs of pregnancy you have now entered the first trimester of your pregnancy journey, better known as the first three months of pregnancy or weeks 1 through 14. During this time your body is undergoing many changes that can sometimes be confusing and worrysome.
The first confusing thing about pregnancy, that we would like to point out, is the way doctors calculate your gestational age. The moment of conception is technically when you first became pregnant, but doctors don't calculate pregnancy this way. Using the date of conception is too inaccurate; since a majority of women don't know the time and day they conceived. Most women, however, can recall when they had their last period. So doctors use the first day of your last menstrual period (LMP) to calculate the length of pregnancy. With the proper information and knowledge, you will know what to expect during this first trimester of pregnancy, as well as how to handle different pregnancy symptoms that are thrown your way. Enjoy this amazing journey that you and your body are about to embark on, because sooner than you think, you will meet the newest tiny addition to your family!
Among the more common early pregnancy symptoms that women experience during pregnancy include nausea, breast tenderness, frequency of urination and increase appetite. All of these experiences are perfectly normal during the first 14 weeks of pregnancy.
You can blame your surging hormones for your uncomfortable pregnancy symptoms in the first trimester. Your elevated hormones (such as human chorionic gonadotropin, progesterone, estrogen, etc.) are supporting your pregnancy and helping it thrive. In fact, did you know that women who don’t have morning sickness are at higher risk for miscarriage? The pregnancy hormones that are causing you to feel nauseous and sick all the time are actually supporting the baby growing inside you!
Fortunately you will find that many of the unpleasant side effects of the first trimester disappear during the second. If you haven't already, be prepared to quit smoking and drinking cold turkey, as these habits could be detrimental to your baby.
During your first trimester you will set up your first prenatal visit. The first prenatal visit is one of the most comprehensive of all visits during your pregnancy. At this time your healthcare practitioner will take a comprehensive medical history and conduct a full physical examination.
Most women will see their provider for the first time between weeks 8 and 10 when they first detect early pregnancy symptoms. Your healthcare provider should discuss with you any significant aspects of your medical & sexual health or family history that may impact your pregnancy. In many instances, your healthcare provider will perform an ultrasound exam to confirm the viability of your pregnancy, and during this time you will be allowed to greet your baby for the first time!
Many women will also be able to hear the baby's heart beat for the first time by about week 12, though it may take a little longer in some cases!
You have made it through the tough, pregnancy symptom-filled first trimester. Beginning the second trimester of pregnancy is a welcome relief for many women, especially those that had severe morning sickness and other intense early pregnancy symptoms.
The second trimester of pregnancy spans between three and six months and is often referred to as the "honeymoon stage" of pregnancy due to the decreased number of pregnnacy symptoms that some women experience.
You are also starting to grow a beautiful pregnant belly in your second trimester. As your pregnancy progresses, you may start feeling more comfortable and proud of your growing baby bump! Embrace your pregnancy and the beautiful body that is transforming around you. You are almost halfway through your pregnancy and so much closer to meeting your bundle of baby joy! In fact, most women start to feel really great about their bodies during the second trimester. Hormones generally start to level off, and most women start 'showing' which is a true testament to their changing physical state.
During the second trimester you will continue to see your healthcare provider every four weeks until approximately week 28, when prenatal visits become more frequent. The symptoms of nausea and fatigue have usually disappeared and you will start to notice physical changes to your body. Most women are able to start wearing maternity clothes during the second trimester, and begin proudly showing off their growing bellies!
The second trimester is also the time when your baby's rapid growth starts. You should be able to feel your baby move between the 17th and 21st week of pregnancy, though some women are able to detect movement even sooner, particularly in second pregnancies. At the end of the second trimester your baby weighs about 1.2 pounds and measures about 8.5 inches. The baby's face and body look more like that of an infant at the time of birth. You may even be able to determine the gender of your baby via ultrasound during the second trimester.
Some women are not able to hear the gallop of their baby's heartbeat for the first time until they approach the second trimester. This is an exciting and dramatic time for both parents.
Other perks that are common during the second trimester include a renewed sense of energy and an increased ability to sleep. Most women find they have to use the bathroom less during the second trimester. One thing you can do to improve your energy during this time even further is start exercising regularly, which will not only help you sleep better but will also help you feel energetic and good about your body throughout your pregnancy week by week.
You are in the third trimester of pregnancy, between six and nine months pregnant. You are only weeks away from meeting your new baby!
As you move out of the relaxing, and exciting second trimester, be prepared for your baby bump to grow even more! During the third trimester, you will continue to put on weight and you may feel like your tummy is about to pop as your due date draws near. Remember to embrace the beautiful body that signifies the healthy growth of your developing son or daughter.
As you get closer and closer to labor and delivery, try to rest as much as possible and obey your healthcare professional's orders so that your delivery will go as seamlessly as possible. Your baby is continuing to grow and gain weight rapidly. A very important part of your baby's development at this time is the maturation of the lungs and respiratory system.
Between 37 and 42 weeks your baby is completely mature and ready for birth. Soon you will be experiencing Braxton Hicks contractions and eventually strong labor pains that will result in you delivering your baby. When you deliver, your baby will weigh on the average of 7.5 pounds and be about 18-21 inches long.
During the third trimester many women start realizing some of the same discomforts they did during the first trimester. Among these include more frequent trips to the bathroom and greater fatigue. Many women also suffer from poor quality sleep during the third trimester, mostly as a result of trying to stay comfortable during the evening.
One thing you can do to improve your comfort level is to sleep on your side with a body pillow wedged between your legs. An additional pillow tucked behind your back will help improve your comfort even further. Some women find that they can only get comfortable while sleeping in a propped up position.
In addition to the feeling that you need to use the bathroom all the time, you might also start experiencing worsening heartburn during the third trimester. Heartburn is common as your baby continues to grow and presses up against your stomach. One of the best things you can do to alleviate heartburn is eat smaller meals, and avoid lying down for the first two hours after eating.
The third trimester is also one of the most exciting for most women, as they approach delivery. All the discomforts of the third trimester are typically mitigated by the expectation that you will soon welcome your beautiful newborn baby into your home.