@ucantstop_me
Apparently in India they use the term "foetus" that early (8 weeks) though we start at 10 weeks. But not sure why he thinks there are unfertilized eggs hanging around the uterus.
@ucantstop_me
The interesting thing is that "twinning" can occur up to about 11 days, around the same time as implantation. Prior to that, if you have a 2-cell zygote, you can take the cells apart and get two identical twins, do it again and get quadruplets, etc. After that watershed point, if you divide the cells, they can never replace the function of the lost cells, causing death or massive fetal deformities.
So if the fertilized egg is a fully realized human with a soul, who gets the soul if it becomes twins or triplets?
@AlphaCentauri cool. The top row is growth on days. 6 day to blastocyst when is when the cells are differentiated, meaning they get the DNA changed to be a skin cell or organ, bone etc
Blastocyst is also when IVF transfers occur.