Men have tubes, too?
I digress, abortion isn't legal everywhere, so that's basically an assumption (unless the OP mentioned it later in the thread or something). That and once the child is conceived, there's the parents religions, moral beliefs, and preferences to using the opportunity to become parents. It becomes a different issue once you find out that you (or your SO) is pregnant, and perspectives for both possible parents may change after the fact, or they may not. Simply saying that they don't have the right is taking it too far in this aspect, accidental pregnancy or not.
Simply put, there are a plethora of factors surrounding the situation, both for the OP and his wife.