Pregnancy countdown
Days until your due date and how many weeks pregnant you are today, from your last period or the date your scan gave you.
Key dates
These terms follow the American College of Obstetricians and Gynecologists (ACOG) definitions. Your clinician may adjust the due date after a dating scan; if so, switch to “I know my due date”.
Questions people ask
How many weeks pregnant am I?
Pregnancy is dated from the first day of your last menstrual period (LMP), not conception. Count the days from LMP to today and divide by 7; 45 days is 6 weeks 3 days.
How is the due date calculated?
Naegele’s rule adds 280 days (40 weeks) to the first day of the last period, assuming a 28-day cycle. For longer or shorter cycles, clinicians often shift the date by the difference. An early ultrasound is the most accurate way to date a pregnancy.
How many babies arrive on their due date?
Only a small share, often quoted as about 4 to 5 percent. Most births happen within the two weeks either side. Full term is 39 weeks 0 days to 40 weeks 6 days (ACOG).
Can I use my ultrasound due date instead?
Yes. Switch to “I know my due date” and enter the date from your scan or clinician. The countdown and week count follow it.
Is this medical advice?
No. It is a countdown and date calculator. Your midwife or doctor sets your official due date and care plan.