If the school made you take it off you could sue them for violations of your civil rights and probably get the aclu to handle your case.
School does restrict what you where, nearly every school has somthing called a "code of conduct" where a dress code is usually defined, whether that be school uniforms or what "inappropriate dress" is. Yes, the ACLU does defend cases like this. One kid in Wyoming or somewhere wore a "Bush: International Terrorist" shirt, which the school told him to take off. He sued with the ACLU's help. Other than that, I've seen no other instance of the ACLU defending someone who was the victim of an unfair dress code, but I do see kids taken to the principals office every day at school for "inappropriate dress". See a slight bias?

I am personaly agenst abortion and would counsle anyone I knew not to get one. But untill the chiled could live outside of the mothers womb Ido not see it as a distinct indavidual and the rights of the mother would superceed its rights.
No one should have the right to end a life, with the possible exception of there own was in danger. If a mother does not want the child, she should give birth and put it up for adoption, which I believe is a more humane way of handling things.