Pregnancy Calculator

How Pregnancy Dating Works

Pregnancy dating begins with your last menstrual period (LMP) because it’s easier to track than the exact moment of conception. While conception typically occurs about 2 weeks after your LMP, medical professionals use the LMP date as the starting point for all pregnancy calculations. For optimal pregnancy health, consider using pregnancy tracking journals to monitor your symptoms and milestones.

Standard Pregnancy Timeline

📅 Full-term pregnancy:

40 weeks (280 days) from LMP

🤱 Trimester breakdown:

1st: Weeks 1-12 | 2nd: Weeks 13-27 | 3rd: Weeks 28-40

The pregnancy timeline is divided into three trimesters, each with distinct developmental milestones and maternal changes. Understanding these stages helps you prepare for what to expect and ensures you receive appropriate prenatal care at the right times.

Factors Affecting Due Date Accuracy

While our calculator provides accurate estimates based on medical standards, several factors can influence the actual timing of your baby’s arrival:

• Cycle Length: Women with longer or shorter cycles may ovulate earlier or later than the standard 14-day assumption.
• Irregular Periods: Unpredictable cycles make it harder to pinpoint ovulation and conception dates.
• First vs. Subsequent Pregnancies: First babies tend to arrive slightly later than subsequent babies.
• Maternal Age: Older mothers may have slightly longer pregnancies on average.
• Genetic Factors: Family history of early or late deliveries can influence timing.
• Multiple Pregnancies: Twins and multiples typically arrive earlier than single babies.
• Medical Conditions: Certain conditions may affect pregnancy length and delivery timing.

Prenatal Care Schedule

Regular prenatal appointments are essential for monitoring your health and your baby’s development. Here’s the typical schedule recommended by healthcare providers. To stay organized, consider using a pregnancy appointment planner to track all your visits and important dates.

Important Pregnancy Tests and Screenings

Throughout your pregnancy, various tests and screenings help ensure both you and your baby remain healthy:

• First Trimester Screening (11-14 weeks): Blood test and ultrasound to assess risk of chromosomal abnormalities.
• Anatomy Scan (18-22 weeks): Detailed ultrasound to check baby’s development and detect any structural abnormalities.
• Glucose Screening (24-28 weeks): Test for gestational diabetes.
• Group B Strep Test (35-37 weeks): Screening for bacteria that could affect delivery.
• Non-Stress Test (after 32 weeks if needed): Monitors baby’s heart rate and movements.

Nutrition and Lifestyle During Pregnancy

Proper nutrition and healthy lifestyle choices are crucial for your baby’s development and your own well-being during pregnancy:

Common Pregnancy Symptoms by Trimester

Understanding what to expect can help you prepare for the changes your body will experience throughout pregnancy:

Preparing for Labor and Delivery

As you approach your due date, preparation becomes increasingly important. Consider taking childbirth classes, creating a birth plan, and packing your hospital bag by 36 weeks.

Remember that only about 5% of babies are born on their exact due date. Most babies arrive within 2 weeks before or after the estimated due date, which is considered normal and healthy.