Week 3 – Gestational Age / Week 1 – Fetal Age
** Gestational age is the age of the pregnancy from the last normal menstrual period (LMP) and fetal age is the actual age of the growing baby.
The embryo is going through lots of basic growth at this time, with the beginning development of the brain, spinal cord, heart and gastrointestinal tract.
Source: American Pregnancy Association