How many months is 5 weeks pregnant?

5 weeks pregnant puts you in month 2 of pregnancy. Week 5 is the first week of that month, which runs to week 8. Providers count in weeks; months are approximate.

How big is the baby at 5 weeks?

At 5 weeks, the baby is about the size of a sesame seed, roughly 0.3 cm long. That is an average; healthy babies vary.

What should I feel at 5 weeks pregnant?

Common signs at 5 weeks include tiredness, sore or tender breasts, a metallic taste, needing to pee more often, mild period-like cramps, and a thin, milky white discharge. Nausea most often starts around week 6, but it can begin now. Plenty of people feel none of this yet. How you feel is not a test of how the pregnancy is going.

Is the baby still implanting at 5 weeks?

No. Implantation happens much earlier. In a study that tracked 189 pregnancies, it took place 6 to 12 days after ovulation, most often on day 8, 9 or 10. That is around week 3 to 4 of pregnancy. By week 5, the embryo is attached to the lining of the uterus and the placenta is beginning to develop.

Is cramping normal at 5 weeks pregnant?

Mild cramping at 5 weeks is common and often feels like a period is about to start. Pain that is different needs checking the same day: pain low down on one side that won't settle, pain in the tip of your shoulder, pain when you pee or poo, or cramps with bleeding. These can be signs of an ectopic pregnancy, where the pregnancy grows outside the uterus. Sudden, severe pain, dizziness or fainting is an emergency.

Is brown discharge normal at 5 weeks pregnant?

Often, yes. Brown means the blood is old and has left the body slowly. Spotting is most common between weeks 5 and 8: in a study of more than 4,500 pregnancies, about 1 in 4 women bled at some point in the first trimester, and most episodes lasted less than 3 days. The exception is watery, dark brown discharge together with one-sided tummy pain. Get that checked the same day, because the two together can point to an ectopic pregnancy.

What should I avoid at 5 weeks pregnant?

Stop drinking alcohol and stop smoking. Keep caffeine under 200 mg a day, and remember that shop-bought coffee often has more than you'd think. Avoid raw or undercooked meat and eggs, unpasteurised milk, some soft cheeses, liver, and shark, swordfish and marlin. Keep taking 400 micrograms of folic acid a day until at least week 12. Check with a pharmacist or your provider before taking any medicine.

5 Weeks Pregnant

At 5 weeks pregnant, your period is about a week late, and a home test has probably just turned positive. The embryo is tiny, only a couple of millimetres long, about the size of a sesame seed, but its brain, spinal cord and heart are already forming. Pregnancy hormones are rising quickly. That can bring tiredness, sore breasts, a metallic taste and needing to pee more often, and for some the first waves of nausea. Many people feel almost nothing yet, and that is normal too. This page explains why a 5-week ultrasound often shows very little, what cramping and brown spotting usually mean this early, and what to avoid from now on.

What trimester is 5 weeks?

Week 5 is in the first trimester, which runs from week 1 to week 12. The second trimester starts at week 13, 8 weeks from now.

Week 5 — first trimester, month 2; 35 weeks to go until your due date.
Baby's size — about a sesame seed, ~0.3 cm.

Not sure it's 5 weeks? Try our due date calculator.

★ The neural tube and early heart begin to form.

How big is your baby at 5 weeks?

Size of a

sesame seed

Length, head to bottom

~0.3 cm

Weight

—

Up from a poppy seed last week to a sesame seed now.

Baby development at week 5

The embryo's major systems start forming. The neural tube — which becomes the brain and spinal cord — begins to develop, and a tiny heart tube starts to form and will soon begin to beat. Three layers of cells are now differentiating into everything from the nervous system to the digestive tract. At about the size of a sesame seed, growth this week is rapid and foundational.

What an ultrasound shows at 5 weeks

At 5 weeks, a vaginal scan usually shows only a small, dark, fluid-filled circle inside the uterus. This is the gestational sac. It first becomes visible at about 5 weeks and grows about 1 mm a day. A small ring inside it, the yolk sac, tends to appear at around 5 and a half weeks. The embryo itself, and its heartbeat, usually can't be seen until about 6 weeks.

So a scan that shows an empty sac, or nothing yet, is often simply too early, especially if you ovulated later than you think. A pregnancy is usually visible once the hormone hCG is above roughly 1,500 to 2,000 mIU/mL, although this varies between clinics. Because a positive test with nothing seen in the uterus can also be a sign of an ectopic pregnancy, your provider may repeat your hCG blood test after two days and scan again a week or two later.

Most people aren't scanned this early. Routine first scans usually happen between 8 and 14 weeks. An early scan is more likely if you have pain or bleeding, have had an ectopic pregnancy before, or conceived with IVF.

Your body at 5 weeks

Rising fatigue as hormone levels climb
Nausea may begin ('morning' sickness can strike any time)
Frequent urination
Heightened sense of smell and food aversions

Your belly at 5 weeks

Nothing shows from the outside at 5 weeks. The uterus is still small and sits low in your pelvis. If your belly feels puffy or your waistband feels tight, that is bloating from the hormone progesterone, which slows digestion.

Mild cramps, a bit like period pains, are common at this stage too. They tend to come and go.

Tips for week 5

Folic acid matters most now — the neural tube is forming
Eat small, frequent snacks to manage early nausea
Rest when you can; first-trimester fatigue is real

5 Weeks Pregnant: your questions

What trimester is 5 weeks?: Week 5 is in the first trimester, which runs from week 1 to week 12. The second trimester starts at week 13, 8 weeks from now.
How many months is 5 weeks pregnant?: 5 weeks pregnant puts you in month 2 of pregnancy. Week 5 is the first week of that month, which runs to week 8. Providers count in weeks; months are approximate.
How big is the baby at 5 weeks?: At 5 weeks, the baby is about the size of a sesame seed, roughly 0.3 cm long. That is an average; healthy babies vary.
What should I feel at 5 weeks pregnant?: Common signs at 5 weeks include tiredness, sore or tender breasts, a metallic taste, needing to pee more often, mild period-like cramps, and a thin, milky white discharge. Nausea most often starts around week 6, but it can begin now. Plenty of people feel none of this yet. How you feel is not a test of how the pregnancy is going.
Is the baby still implanting at 5 weeks?: No. Implantation happens much earlier. In a study that tracked 189 pregnancies, it took place 6 to 12 days after ovulation, most often on day 8, 9 or 10. That is around week 3 to 4 of pregnancy. By week 5, the embryo is attached to the lining of the uterus and the placenta is beginning to develop.
Is cramping normal at 5 weeks pregnant?: Mild cramping at 5 weeks is common and often feels like a period is about to start. Pain that is different needs checking the same day: pain low down on one side that won't settle, pain in the tip of your shoulder, pain when you pee or poo, or cramps with bleeding. These can be signs of an ectopic pregnancy, where the pregnancy grows outside the uterus. Sudden, severe pain, dizziness or fainting is an emergency.
Is brown discharge normal at 5 weeks pregnant?: Often, yes. Brown means the blood is old and has left the body slowly. Spotting is most common between weeks 5 and 8: in a study of more than 4,500 pregnancies, about 1 in 4 women bled at some point in the first trimester, and most episodes lasted less than 3 days. The exception is watery, dark brown discharge together with one-sided tummy pain. Get that checked the same day, because the two together can point to an ectopic pregnancy.
What should I avoid at 5 weeks pregnant?: Stop drinking alcohol and stop smoking. Keep caffeine under 200 mg a day, and remember that shop-bought coffee often has more than you'd think. Avoid raw or undercooked meat and eggs, unpasteurised milk, some soft cheeses, liver, and shark, swordfish and marlin. Keep taking 400 micrograms of folic acid a day until at least week 12. Check with a pharmacist or your provider before taking any medicine.

Useful at week 5

hCG levels by week — typical ranges at 5 weeks and why one number means little
Implantation bleeding — how early spotting differs from a period
Early pregnancy symptoms — the first signs, and when each usually starts
Foods and activities to avoid — the full list, item by item
Coffee in pregnancy — what 200 mg of caffeine looks like

← All weeks: the full pregnancy week-by-week guide

Sources

Checked against the following public guidance on October 2, 2026. Advice can differ between countries; your doctor, nurse or midwife can apply it to you.