Find your due date and get a week by week breakdown of what to expect — what's happening, what to buy, and what to actually watch out for.
The standard method (Naegele's Rule) adds 280 days (40 weeks) to the first day of your last menstrual period. This assumes a 28-day cycle and ovulation on day 14. Your doctor may adjust this based on ultrasound measurements, which are more accurate in early pregnancy.
Only about 5% of babies are born on their actual due date. Most arrive within 2 weeks before or after. A full-term pregnancy is considered 39-40 weeks, but 37-42 weeks is the normal range.