Your pregnancy, week by week
The pregnancy timeline above turns your due date into a calendar of 42 weeks. Each row shows the dates of one week of pregnancy, counted from the first day of your last period, along with the trimester it belongs to. If you are currently pregnant, your current week is highlighted.
The three trimesters
First trimester (week 1 to week 13 + 6 days)
Weeks 1 and 2 are counted from the first day of the last period, before conception has happened, which is why “4 weeks pregnant” is usually only about two weeks after conception. Implantation happens in week 3–4, and a home pregnancy test usually turns positive around the time of the missed period. The first trimester is when the major organs begin to form, and it is also when many people have their first prenatal appointment and an early ultrasound. An ultrasound in this trimester is the most precise way to confirm or adjust an estimated due date.
Second trimester (week 14 to week 27 + 6 days)
For many people the second trimester feels the most comfortable. Early nausea often eases, the bump becomes visible and the first movements (“quickening”) are commonly felt somewhere between 16 and 22 weeks. A detailed anatomy scan is typically offered between 18 and 22 weeks, and screening for gestational diabetes is commonly done between 24 and 28 weeks.
Third trimester (week 28 until birth)
The third trimester is about growth and preparation. Prenatal visits usually become more frequent, and your care team will monitor growth, position and wellbeing. A pregnancy is considered early term from 37 weeks, full term from 39 weeks, late term from 41 weeks and post-term from 42 weeks — the estimated due date sits at exactly 40 weeks.
Pregnancy week by week: what typically happens
Once you know your due date, every week of pregnancy has a date. This table summarises what commonly happens in each week, with a rough size comparison for the baby. Timing of tests varies by provider and country — treat it as a general guide.
| Week | Trimester | Baby’s size (roughly) | What typically happens |
|---|---|---|---|
| 4 weeks | First | a poppy seed | Implantation has usually completed and the pregnancy hormone hCG is rising. |
| 5 weeks | First | a sesame seed | The neural tube — which becomes the brain and spinal cord — is forming, and the heart is beginning to develop. |
| 6 weeks | First | a lentil | Cardiac activity may be visible on a transvaginal ultrasound around now. |
| 7 weeks | First | a blueberry | The brain is developing rapidly and small buds that will become arms and legs have appeared. |
| 8 weeks | First | a raspberry | Many people have their first prenatal appointment somewhere between 8 and 10 weeks, sometimes with a dating ultrasound to confirm the due date. |
| 9 weeks | First | a cherry | The embryonic period is coming to an end; from around 10 weeks the developing baby is usually called a fetus. |
| 10 weeks | First | a strawberry | Cell-free DNA screening (NIPT) can be offered from about 10 weeks, depending on where you receive care. |
| 11 weeks | First | a fig | The window for the nuchal translucency scan, part of first-trimester screening, typically opens at 11 weeks and runs to about 13 weeks 6 days. |
| 12 weeks | First | a lime | The uterus is starting to rise above the pelvis. |
| 13 weeks | First | a lemon | This is the last week of the first trimester. |
| 14 weeks | Second | a peach | The second trimester begins. |
| 15 weeks | Second | an apple | Second-trimester blood screening (such as the quad screen) is commonly offered between about 15 and 22 weeks. |
| 16 weeks | Second | an avocado | Some people begin to feel the first flutters of movement, known as quickening — often later, up to about 20–22 weeks, in a first pregnancy. |
| 17 weeks | Second | a pomegranate | The skeleton is changing from soft cartilage to bone, and fat stores are beginning to form. |
| 18 weeks | Second | a bell pepper | The window for the detailed anatomy scan typically opens at 18 weeks. |
| 19 weeks | Second | a mango | A protective coating called vernix is forming on the skin. |
| 20 weeks | Second | a banana | You are halfway to your due date. |
| 21 weeks | Second | a carrot | Movements are becoming stronger and more regular. |
| 22 weeks | Second | a papaya | The senses are developing, and the baby may begin to respond to sounds. |
| 23 weeks | Second | a grapefruit | Rapid weight gain for the baby continues through the coming weeks. |
| 24 weeks | Second | an ear of corn | Glucose screening for gestational diabetes is commonly done between 24 and 28 weeks. |
| 25 weeks | Second | a cauliflower | The baby is putting on fat and the skin is becoming less translucent. |
| 26 weeks | Second | a zucchini | The eyes typically begin to open around 26 to 28 weeks. |
| 27 weeks | Second | a head of lettuce | This is the last week of the second trimester. |
| 28 weeks | Third | an eggplant | The third trimester begins. |
| 29 weeks | Third | a butternut squash | The baby’s movements may feel stronger but more cramped as space decreases. |
| 30 weeks | Third | a cabbage | Many people notice more tiredness, heartburn or difficulty sleeping as the bump grows. |
| 31 weeks | Third | a coconut | The baby is gaining weight quickly and developing the ability to regulate body temperature. |
| 32 weeks | Third | a squash | In a common US schedule, visits are every two weeks between 28 and 36 weeks. |
| 33 weeks | Third | a pineapple | The bones are hardening, although the skull stays soft and flexible for birth. |
| 34 weeks | Third | a cantaloupe | Many people start to prepare a birth plan and hospital bag around now. |
| 35 weeks | Third | a honeydew melon | Space is tight, so movements may feel different — but you should still feel regular movement. |
| 36 weeks | Third | a romaine lettuce | Group B strep screening is commonly done between 36 and 37 weeks 6 days, and visits often become weekly. |
| 37 weeks | Third | a winter melon | From 37 weeks a pregnancy is considered early term. |
| 38 weeks | Third | a pumpkin | The baby continues to gain weight; most organs are ready for life outside the womb. |
| 39 weeks | Third | a small watermelon | From 39 weeks a pregnancy is considered full term. |
| 40 weeks | Third | a watermelon | This is your due date week. |
| 41 weeks | Third | a watermelon | From 41 weeks a pregnancy is late term. |
| 42 weeks | Third | a watermelon | From 42 weeks a pregnancy is post-term. |
Week-by-week guides
For a short guide to a particular week, including what is typically happening and the dates for that week, choose one below:
4 weeks 5 weeks 6 weeks 7 weeks 8 weeks 9 weeks 10 weeks 11 weeks 12 weeks 13 weeks 14 weeks 15 weeks 16 weeks 17 weeks 18 weeks 19 weeks 20 weeks 21 weeks 22 weeks 23 weeks 24 weeks 25 weeks 26 weeks 27 weeks 28 weeks 29 weeks 30 weeks 31 weeks 32 weeks 33 weeks 34 weeks 35 weeks 36 weeks 37 weeks 38 weeks 39 weeks 40 weeks
Planning with your timeline
A calendar makes it easier to plan appointments, announcements and time off. Combine it with the Pregnancy Due Date Calculator for milestone dates, the Pregnancy Week Calculator for a quick “how far along am I?”, and the Add Weeks to Date calculator if you need to count a number of weeks from any day.