Amendment IX - Construction of Constitution. Ratified 12/15/1791.
The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.
People have been trying for more than 200 posts to get you to specifically say why it should NOT be a right to have an abortion. Here in the US, something is a right until it is legislated that is is not a right. In order to legislate something, you usually have to have a reason to do so.
So basically, it is a right until otherwise shown.
Of course, biblical creationists are committed to belief in God's written Word, the Bible, which forbids bearing false witness; --AIG (lest they forget)