Abortion.

"It's part of my body."

It's in your body, of course. I don't think anyone has ever tried to deny that.

But a fetus has its own body parts, its own DNA, its own life. It it living on its own- with the nutrients it gets from the mother. But it is, however, living on its own. It doesn't borrow any heartbeats from the mother, she does not make his heart beat, it beats all of his own.

It's a seperate human being that temporarily needs the help of another one. 

Like for example, a newborn baby inside a incubator (machine that produces heat for babies that can't keep themselves warm). It's inside the machine but that doesn't make it a machine part, does it?

It's operating on its own, while using the heat from the machine to stay alive. Many many many people have been in a position where they've needed help from a machine to live (oxygen, blood transplant, ect). I'm glad they were allowed to live.