How long does it take for a fertilized egg to implant in the uterus? A fertilized egg is formed when a sperm and egg meet. This process is called fertilization. Sperm and egg combine in the ampulla of the fallopian tube to form a fertilized egg. The fertilized egg is transported to the uterus by the movement of the cilia of the fallopian tube. During the transportation process, the fertilized egg continues to develop, first forming a double pronucleus, then a 2-cell embryo, a 4-cell embryo, an 8-cell embryo, a morula, and a blastocyst. This process takes about 2-3 days. [Complete 120 episodes MP3] Hao Jingfang’s children’s enlightenment course on all things downloaded from the network disk grew into a blastocyst, and at the same time it came to the uterine cavity. The embryo will swim around in the uterine cavity, looking for a suitable place to implant. This process About 5-7 days.