Do fetuses feel pain?

I saw a headline this morning that said that a challenge to Georgia's "fetal pain" bill would be  heard in court today:

http://www.ajc.com/ap/ap/social-issues/hearing-set-in-challenge-to-georgia-abortion-law/nTbhL/

Supporters of the bill believe that fetuses can feel pain as early as 20 weeeks. Others say that this is false and that pain is a psychological experience and that fetuses that young do not have the consciousness and context to feel pain.

What do you think? Is there a strong enough answer on either side to base a law off of it?

Lisa