You are making an assumption that I think a 4 week old fetus merits protection. I have no clue if it does or doesnt. Again, I don't have the answers, I just think the stand we have chosen is arbitrary. I also think that anyone agaionst abortion automatically assumed to be so on religious grounds, and thats just not true.
Here is my view. At the point a baby is born, they have protection under the law. 1 hour earlier, the baby was esentially the same phsically. The only difference is that it was connect to and inside its mother. 1 week earlier it was not very different physically, but 6 months earlier the difference was huge.
My point is we are arguing the wrong things. Physical connection is irrelivant. Releigion is irrelivant. Until society logically defines life and determines a test for when it begins, we will have no answers. Givin this, I have a hard time seeing why both sides are so passionate in their views. Technically, neither side has a leg to stand on because we dont yet completely understand the problem.