The first trimester is an emotional rollercoaster filled with moments of joy, anxiety, excitement and dread. And the physical changes are just as intense — from extreme exhaustion and morning sickness to constipation and sore breasts. It might feel like the first trimester stretches on for an eternity, but in reality it starts on day one of your last menstrual period and extends through week 13, day 6. Hang in there — many people find the second trimester brings a welcome energy boost.
It might feel like the first trimester stretches on for an eternity, but in reality it starts on day one of your last menstrual period and extends through week 13, day 6. That means by the time you get a positive pregnancy test, you're already considered four or more weeks pregnant. Your estimated due date is calculated from the first day of your last period — so the first trimester is roughly the first three months of pregnancy.
Select your week below to track each stage of your first trimester.
Fingers, toes, and tiny facial features start to take shape. Week 8 often feels like a practical turning point becaus…
Full guide includes baby development, symptoms, nutrition, FAQs, and listen-along audio.
Read full week 8 guide →Size comparisons are playful approximations and every pregnancy is different. This is general information, not medical advice — your doctor or midwife is your best guide.
Tap any week for the full guide — development, symptoms, nutrition, FAQs, and listen-along audio.
Week 1
Just the beginning
Pregnancy is counted from the first day of your last period, so week 1 is before conception. Week 1 can feel abstract…
Read full guide →Week 2
A tiny spark
Your body is preparing to release an egg; conception usually happens around the end of this week. Your body is moving…
Read full guide →Week 3
About the size of a a cluster of cells
A fertilised egg becomes a tiny ball of cells and begins its journey to the womb. If conception happens this week, th…
Read full guide →Week 4
About the size of a poppy seed
The embryo settles into the womb lining; a positive test may show around now. Implantation is often happening around…
Read full guide →Week 5
About the size of a sesame seed
The tiny heart and basic structures begin to form. This is one of the most active early-building weeks, even if from…
Read full guide →Week 6
About the size of a lentil
A flickering heartbeat may be detected on an early scan. Week 6 is memorable because an early scan may pick up a flic…
Read full guide →Week 7
About the size of a blueberry
Little limb buds appear and the brain is developing fast. There is a lot of visible shaping happening now, even if yo…
Read full guide →Week 8
About the size of a raspberry
Fingers, toes, and tiny facial features start to take shape. Week 8 often feels like a practical turning point becaus…
Read full guide →Week 9
About the size of a grape
The embryo is now called a foetus and is moving (though you can't feel it yet). One lovely milestone this week is tha…
Read full guide →Week 10
About the size of a strawberry
Vital organs are formed and beginning to function. Week 10 is a reassuring milestone because the basic organ systems…
Read full guide →Week 11
About the size of a fig
Tiny tooth buds and nail beds are forming. Week 11 often feels like a bridge between the roughest early symptoms and…
Read full guide →Week 12
About the size of a lime
Reflexes are developing; the riskiest early phase is easing. Week 12 is a landmark week because dating or nuchal scan…
Read full guide →Week 13
About the size of a pea pod
Fingerprints are forming and the body is catching up with the head in size. You are closing out the first trimester,…
Read full guide →Not sure if you're pregnant? See early signs →
The early weeks and months of pregnancy can be physically and emotionally taxing. Those first trimester hormones are no joke — they can leave you feeling exhausted, nauseous and weepy, sometimes all before you've even told anyone you're expecting.
Got that queasy feeling in your tummy? Retching or vomiting is a common affliction in early pregnancy, affecting anywhere from 50 to 90 percent of moms-to-be. It's thought to be linked to rising hCG hormones. Despite the name, morning sickness can strike at any time of day. Small, frequent meals and a prenatal vitamin taken with food can help. If you can't keep anything down, call your provider.
Well before that adorable bump appears, you'll feel like your belly has expanded. But in the early weeks of pregnancy, that's not baby — that's just bloat. Progesterone relaxes smooth muscle throughout your body, including your gastrointestinal tract, which slows digestion and can cause gas, bloating and constipation. Stay hydrated and eat plenty of fibre.
Tender, swollen breasts are often one of the earliest signs of pregnancy. Hormonal surges and increased blood flow can make your breasts feel sore and heavy. Other breast changes — darkening areolas, visible veins — are normal and usually ease as your body adjusts.
Ready to go beyond the basics? Here you'll find the latest data, expert insight and proven advice on pregnancy symptoms you may encounter — from everyday side effects to the more uncommon ones that may take you by surprise.
Can You Take Gas-X While Pregnant? How to Relieve Pregnancy Gas
When Does Implantation Occur? Experts Explain the Timeline
Pregnancy Hormones: The Roles They Play and Symptoms They Cause
18 Things to Know About Your Second Pregnancy
What Does It Mean If You Have Protein in Your Urine During Pregnancy?
What's the Deal With Pregnancy Acne? (And When Will It Go Away?)
What to Know About the Linea Nigra (aka That Line on Your Belly)
You may not look pregnant yet, but your body is working overtime. Over the first 13 weeks, a veritable seed grows into a tiny human with organs and systems — lungs, heart, brain, liver, spine, limbs and genitalia. Facial features, toes and fingernails all take shape. By the end of the first trimester, baby has a heartbeat you can often hear on ultrasound, and the risk of miscarriage drops significantly.
There are a few hard rules to follow in the coming weeks to keep you and baby as safe as possible.
First Trimester
Pregnancy is chock full of "what ifs" and nagging questions. Here, we break down a few of the most common first trimester inquiries:
A: Yes — don't be surprised if you experience some mild discomfort, similar to menstrual cramps early in pregnancy. It's possible you might even feel this before your missed period; it could be implantation cramps (when the egg burrows into your uterus). Your uterus is rapidly growing throughout the first trimester, which can cause a pulling, stretching or cramping sensation. If abdominal pain is severe or accompanied by heavy bleeding, reach out to your doctor right away.
As baby grows in your belly, you'll want to take the proper precautions to make sure you and baby are safe and healthy. Explore our guides below to learn everything you need to know about pregnancy safety in the first trimester and beyond.
Whether you need help choosing baby's name or figuring out your due date, our free tools are here to help.
Join our warm WhatsApp community of parents and parents-to-be — share the wins, the worries, and everything in between.
Join the WhatsApp communityMorning sickness often starts around weeks 5–6 and can happen at any time of day. Here are the symptoms people ask about most in the first trimester.
First trimester
Nausea and vomiting in early pregnancy — common, usually harmless, and eases by mid-pregnancy for most people.
Read GuideFirst–Third trimester
Deep tiredness driven by pregnancy hormones and the physical demands of pregnancy — common in the first and third trimesters.
Read GuideFirst–Third trimester
Tender, changing breasts are a very early and very normal pregnancy sign — but any new lump or skin change still needs checking.
Read GuideFirst–Second trimester
A sudden dislike of certain foods or smells, common in early pregnancy and usually easing over time.
Read GuideFirst–Third trimester
Weeing more often is common in early and late pregnancy — harmless, but pain or burning may mean a UTI needing treatment.
Read GuideFirst–Third trimester
Emotional ups and downs driven by pregnancy hormones — common, usually manageable, and always worth talking about if they feel too much.
Read Guide
