Doppelherz Maternity Supplement Capsules Vital Pregna
412,000₫562,000₫
9.010k sold · ★ 4.9
Buy on ShopeeDue date and pregnancy week calculator
Pregnancy is counted from the first day of your last period, not from conception. So when your period is about a week late, you are usually already around five weeks pregnant. The tool below estimates your week, due date and the usual check-up milestones.
How the due date is worked out
The usual method (Naegele's rule) adds 280 days, or 40 weeks, to the first day of your last period, assuming a 28-day cycle. Longer or shorter cycles shift ovulation, so the tool lets you choose a cycle from 21 to 40 days. The NHS notes that pregnancy normally lasts 37 to 42 weeks from the first day of your last period, so the due date is a midpoint, not a promise.
An ultrasound gives a more accurate date
If you are unsure of your period date, have irregular cycles or recently stopped hormonal contraception, a date-based estimate can be off. WHO recommends at least one ultrasound before 24 weeks to estimate gestational age. When the scan and your dates disagree, your doctor decides which to use.
Antenatal milestones worth knowing
WHO (2016) recommends at least eight antenatal contacts: the first within 12 weeks, then at 20, 26, 30, 34, 36, 38 and 40 weeks. Hospitals in Vietnam also highlight a few key scans:
- Weeks 11–13: nuchal translucency scan and screening tests.
- Weeks 21–24: detailed anomaly scan.
- Weeks 30–32: growth, placenta and amniotic fluid check.
Your own schedule is set by your obstetrician based on your health and your baby's.
When to get help straight away
Contact a doctor or go to a hospital straight away if you have moderate to heavy vaginal bleeding; bleeding with tummy pain, cramps or fever; pain low down on one side; sudden severe pain, dizziness, fainting or looking very pale; or vomiting so much you cannot keep food or fluids down for 24 hours. NHS and Mayo Clinic advise not waiting with these signs.
Popular picks
Show moreQuestions people ask
Is pregnancy counted from conception or from my last period?
From the first day of your last period. With a 28-day cycle, conception usually happens about two weeks later, so the pregnancy week is roughly two weeks ahead of conception.
How accurate is the due date?
It is an estimate. A normal pregnancy lasts 37 to 42 weeks, and an early scan is usually more accurate than period dates. Go by the date your doctor records.