Prenatal Development By ak001930 Period: Feb 10, 2017 to Feb 10, 2017 Zygote First two weeks Period: Feb 10, 2017 to Feb 10, 2017 Embryo Week 3-8 Period: Feb 10, 2017 to Feb 10, 2017 Fetus 9 week - birth Period: Feb 10, 2017 to Feb 10, 2017 First trimester 1-13 weeks Period: Feb 10, 2017 to Feb 10, 2017 Second Trimester 14-26 weeks Period: Feb 10, 2017 to Feb 10, 2017 Third Trimester 27-40 weeks Period: Feb 10, 2017 to Feb 10, 2017 Week of sex detection 16 weeks Period: Feb 10, 2017 to Feb 10, 2017 Week of viable 24 weeks Period: Feb 10, 2017 to Feb 10, 2017 Full term pregnancy 40 weeks