what is your definition of person?
if its "human individual", then a fetus is a person. if you wanna venture into a deep philosophical debate about what constitutes personhood, thats not what conservatives care about when it comes to this topic. they only care about a fetus being a human being.
The real question is when does it go from just a multicellular organism to a person though.
I doubt anyone but the most avid religious people would be against emergency pills, which might as well be day 1 abortions as they're designed to kill an already fertilized egg.
On the other hand, i doubt even the most avid pro-choicer would support a month 9 "abortion", since at that point it would literally just be giving birth early then killing a baby, so taking out all biases like religion, feminism, anti feminism or whatever, there clearly is a point of no return that people can somewhat tell.
In places where abortions are legal i believe the limit is about 24 weeks, but i'm not really qualified to actually tell when it crosses a certain "humane" treshold.
I do think it speaks a lot that so much people would put the rights of a barely developed 1-2 month embryo over the rights of the mother carrying it though.