I think whether it has personhood or not is irrelevant. If it has no personhood I definitely have the right to evict it from my body at any time. If it does have personhood I definitely have more rights than ever to evict it from my body because no other human has the right to use my organs to sustain their own life ar the risk and expensive of my health.

And just to clarify, a single celled human blastocyst is still human. It is literal human DNA.

People always get stuck on the when life begins or the when it's considered human argument. Scientifically speaking it is always alive and it is always genetically human (sperm and ova are alive, we come from living material and develop from there). There is no denying those facts. The word everyone is looking for is personhood.