Fetal Development Timeline By Imcgillicuddy Jan 12, 2018 Fertilization Jan 24, 2018 Pronuclei join together Feb 2, 2018 First round of mitosis Feb 9, 2018 Second round of mitosis Feb 24, 2018 Third round of mitosis Apr 6, 2018 Morula formed Apr 6, 2018 64 cell embryo called a blastocyst Aug 28, 2018 Hatching Aug 28, 2018 Implantation Aug 28, 2018 Ectopic pregnancy could occur Oct 15, 2018 hcg begins to be secreted Oct 15, 2018 disc with streak on the underside forms mesoderm Dec 26, 2018 first missed period May 19, 2019 heart begins to beat Aug 25, 2019 neural tube forms Mar 26, 2020 face plates forming Apr 19, 2020 cleft lip or palate may occur Oct 4, 2020 muscles form, webbed hands and feet Mar 21, 2021 fingers and toes separate, eyes and ears form Apr 14, 2021 genitalia begins to differentiate Aug 7, 2022 chorionic villi sampling can be performed Jun 10, 2023 amniocentesis can be performed Oct 28, 2029 eyes open, fat added under skin