The vagina, the cervix and the fallopian tubes are in open contact with the outside world, much like the digestive system that runs from the mouth down to the anus. Everything that passes through the digestive system is not in your body, not in your cells. You carry it around with you, but it isn’t in you. In the same way, the mother carries her baby, not in her cells, but in a cavity within her that is in open contact with the outside world. She carries you, but you are not in her, so you do not belong to her.
Ancient philosophies, ancient religions such as Hinduism proclaim: ‘a child is its own entity’, which makes sense. Even the egg that comes together with the sperm during conception is entirely separate from the mother. The moment the egg is secreted from the ovary, it becomes separated from the mother. The same happens with the secretion of the sperm cell: it becomes at that moment separated from the father. Nowadays, it is also possible for fertilisation to take place outside of the womb (in vitro). Therefore, fertilisation does not necessarily have to take place inside of the mother.
The fertilised egg cell is completely autonomous.
Many mothers will say to their child: ‘I was pregnant with you and you are part of me’. This is not an accurate statement (and this is very important): from the moment of conception you were already in the outside world; never have you actually been in the cells, in the consciousness of another person!
That your mother developed an umbilical cord for you and shared blood with you does not mean that your mother can claim you. A child is its own entity from the moment of conception. It only needed the environment of the womb to grow.