Pregnancy lasts about 40 weeks and transforms nearly every system in your body. It brings waves of nausea, surges of energy, strange new cravings, a shifting center of gravity, and eventually the unmistakable sensation of another person moving inside you. The experience is divided into three trimesters, each with its own physical reality and emotional texture.
The First Trimester: Weeks 1 Through 12
Before you look pregnant, you’ll feel it. The first trimester is driven by a sharp rise in progesterone and other hormones that sustain the pregnancy but also hijack your digestive system, your energy levels, and your emotions. Fatigue hits early and hard. Many women describe a bone-deep exhaustion that no amount of sleep seems to fix, and it can start within the first few weeks.
Nausea is the hallmark symptom of early pregnancy, affecting up to 70% of women. Despite the name “morning sickness,” it can strike at any hour. It typically begins between weeks 6 and 8, peaks somewhere between weeks 10 and 16, and usually resolves on its own by weeks 16 to 20. For some women it’s mild queasiness that comes and goes. For others it means daily vomiting that disrupts work and daily life.
Beyond nausea, the first trimester brings a constellation of smaller disruptions. Your breasts become tender and swollen. You urinate more frequently because your blood volume is increasing and your kidneys are working harder. Progesterone slows your entire digestive tract, which can cause constipation and heartburn. Food cravings and strong aversions appear seemingly at random. You might suddenly find the smell of coffee unbearable or desperately want foods you never cared about before.
Emotionally, the first trimester can feel isolating. Many people wait to share the news until after week 12, so you may be quietly dealing with all of this while going about your normal routine. Mood swings are common, fueled by hormonal shifts combined with the sheer weight of what’s happening.
The Second Trimester: Weeks 13 Through 27
The second trimester is widely considered the most comfortable stretch of pregnancy. Nausea fades for most women, energy returns, and you start to visibly show. Your uterus, which started the size of a pear, is now expanding rapidly. By the end of pregnancy it will be roughly the size of a watermelon.
The defining moment of the second trimester is feeling the baby move for the first time, an event called quickening. This usually happens between weeks 18 and 20, though first-time mothers sometimes notice it a bit later. Early movements feel like flutters or bubbles, often compared to butterflies in your stomach. As the weeks progress, those flutters become unmistakable kicks, rolls, and even flips. By around week 28, the movements settle into more consistent, predictable patterns.
Your body changes visibly during these months. A dark line called the linea nigra may appear running down the center of your belly. The skin around your nipples can darken. Stretch marks may show up on your belly, breasts, thighs, or buttocks. Some women experience round ligament pain, a sharp or aching sensation on the sides of the lower abdomen caused by the stretching of tissues that support the uterus. Mild swelling in your hands, feet, and ankles is also normal as your body retains more fluid.
Inside, your baby is developing rapidly. By week 13, bones in the skull and limbs begin to harden. The lungs start producing a substance that will eventually allow them to inflate with air after birth. By the end of the second trimester, around week 27, the baby’s nervous system is maturing and a layer of fat is forming beneath the skin. Some babies born prematurely at this stage can survive outside the womb, though they need intensive medical support.
The Third Trimester: Weeks 28 Through 40
The final stretch of pregnancy is physically the most demanding. The baby is gaining weight quickly, and so are you. Your center of gravity shifts forward, putting strain on your lower back. Shortness of breath is common because the growing uterus pushes up against your diaphragm. You may find yourself winded just climbing a flight of stairs.
Braxton Hicks contractions, sometimes called “practice contractions,” become noticeable for most women during the third trimester, though some feel them as early as the second. These are irregular tightenings of the uterus that are more uncomfortable than painful. They don’t follow a predictable pattern, don’t get closer together over time, and eventually stop on their own. They tend to increase in frequency and intensity as your due date approaches, which can make it tricky to distinguish them from real labor. The key difference: true labor contractions come at regular intervals and steadily intensify.
Sleep becomes difficult. Between the need to urinate frequently, heartburn that worsens when lying down, and the challenge of finding a comfortable position around a large belly, unbroken sleep is rare. Many women also experience restless legs, hip pain, or pelvic pressure as the baby drops lower in preparation for birth.
Weight Gain and Body Changes
Weight gain is a normal and necessary part of pregnancy, but the recommended amount depends on your pre-pregnancy BMI. For someone who started at a normal weight (BMI 18.5 to 24.9), the CDC recommends gaining 25 to 35 pounds total. If you were overweight before pregnancy, the target is 15 to 25 pounds. For those who were underweight, 28 to 40 pounds. And if you’re carrying twins, the numbers roughly double, with 37 to 54 pounds recommended for a normal-weight starting point.
This weight isn’t all baby. It includes the placenta, amniotic fluid, increased blood volume, larger breasts, extra fat stores your body builds to support breastfeeding, and the uterus itself. Most of the gain happens in the second and third trimesters.
Signs That Labor Is Approaching
In the final weeks, your body sends signals that labor is getting closer. One early sign is “lightening,” when the baby drops lower into your pelvis. You may notice you can breathe more easily but feel increased pressure in your pelvis and need to urinate even more often. Period-like cramps that come and go over a few days, felt in the abdomen or lower back, are another indicator.
You may lose your mucus plug, a thick discharge that sealed your cervix throughout pregnancy. This can happen days or even weeks before labor starts, so it’s not an urgent sign on its own. When true labor begins, contractions become regular, getting stronger and closer together over time. Your water breaking, the rupture of the amniotic sac, is often one of the last signs and doesn’t always happen before you get to the hospital.
Recovery After Birth
Pregnancy doesn’t end cleanly at delivery. Your body needs weeks to recover regardless of whether you had a vaginal birth or a cesarean section. One of the most immediate experiences is lochia, the vaginal discharge your body produces as the uterus sheds its lining. It lasts up to six weeks, sometimes as long as eight, and moves through distinct stages.
In the first three to four days, the discharge is dark or bright red and flows like a heavy period, sometimes with small clots. Over the next week or so it becomes pinkish-brown, thinner, and more watery. By around day 12, it lightens to a yellowish-white discharge with little to no blood, and this final stage tapers off gradually over the remaining weeks. Bloody discharge typically lasts about two weeks total.
Hormone levels drop sharply after delivery, which commonly triggers mood swings, tearfulness, and irritability in the first week or two. This experience, sometimes called the “baby blues,” affects a large majority of new mothers and usually passes on its own. When low mood persists beyond two weeks or feels overwhelming, it may signal something more serious that benefits from professional support.
Prenatal Care Throughout Pregnancy
Prenatal visits are scheduled roughly every four weeks during the first trimester, becoming more frequent as pregnancy progresses. In the third trimester, you’ll typically see your provider every two weeks and then weekly in the final month. Early visits focus on confirming the pregnancy, establishing a due date (often with an ultrasound), and running baseline blood work. A detailed anatomy ultrasound is usually performed around week 20 to check the baby’s development. Glucose screening for gestational diabetes is typically done between weeks 24 and 28. These visits are also where you track weight gain, blood pressure, and the baby’s growth, all the routine checkpoints that help catch problems early.