Prenatal Development By austyn8214 Jan 1, 2017 Start of Period of Zygote First 2 weeks of pregnancy Jan 1, 2017 Start of First Trimester week 1-12 Jan 15, 2017 End of the Period of Zygote Jan 22, 2017 Start of the Period of Embryo 3-8 Weeks Feb 19, 2017 End of the Period of Embryo Feb 26, 2017 Start of the Period of Fetus 9-40 weeks Apr 2, 2017 Start of Second Trimester week13-27 May 7, 2017 week of sex detection 18-20 weeks May 28, 2017 week of viable birth 23 weeks Jul 16, 2017 Start of Third Trimester week 28-birth Oct 1, 2017 End of Period of Fetus Oct 1, 2017 full term pregnancy 40 weeks
