Pregnancy weeks are counted from the first day of your last menstrual period (LMP).
Evaluation of gestation emedicine.[Accessed July 2017] Morin L, Cargill Y, Glanc P et al. Ultrasound Evaluation of First Trimester Complications of Pregnancy.
Multiple pregnancy: antenatal care for twin and triplet pregnancies CG129.
Also the information provided on my blog is designed to provide helpful information about the topic and are made with the best of my knowledge therefore is not intended to diagnose or treat any medical condition, For diagnosis or treatments on any medical problems consult your own physician.
It's also a chance for you to see your baby for the first time. If you have one, you may find it happens between 11 weeks and 14 weeks of your pregnancy, along with your prenatal screening tests.
However is not until we measure the Crown rump length ( CRL ) that the DUE DATE is set, here is why…