When does an embryo become a fetus?

In these first three months the embryo goes through organogenesis and develops body organs, its heart beats after the fourth week, brain waves can be monitored after six weeks, and by the eighth week all major body parts are present. At the end of the trimester the embryo has matured into a fetus

Around the ages of 7-12

Answergoing for a brief walk ahead of time and stretching afterward;