When does pregnancy start counting

1. First Day of Last Menstrual Period (LMP): The counting begins with the first day of your last menstrual period. Even though conception usually occurs about two weeks later, the LMP is used as the standard reference point.
2. Divide Pregnancy into Trimesters:
   • First Trimester: Weeks 1-12
   • Second Trimester: Weeks 13-27
   • Third Trimester: Weeks 28-40
3. Gestational Age: Gestational age refers to the age of the pregnancy in weeks. For example, if you are 10 weeks pregnant, it means that 10 weeks have passed since the first day of your last menstrual period.
4. Due Date Calculation: The estimated due date (EDD) is often calculated based on the first day of the LMP. Healthcare providers may also use ultrasound measurements to refine the due date, especially if there are variations in menstrual cycle length or if there are uncertainties about the LMP.

It’s important to note that individual variations in menstrual cycle length and irregularities can affect the accuracy of due date calculations. Ultrasound dating can provide a more accurate estimate of gestational age, and healthcare providers may adjust the due date based on this information.

Always consult with your healthcare provider for personalized information and advice regarding your pregnancy, including due dates and the progression of your pregnancy. They can provide more accurate information based on your specific circumstances.