How about this? I have sex with you (this is not an image you want in your head. Sorry.). I do not tell you I am HIV positive. I infect you. I have that right? Absolutely not. Because- and this is where it ties in to abortion. I am affecting someone else's body. The baby I kill is not part of me.
And I will tell you before you bring up the obvious next question- I declined an abortion for rape. We didn't know whose she was biologically until she was born. In my case, I knew who her mother was. In my husband's case, "I knew who I wanted to kill and it wasn't the baby." We have a positive duty to each other.