Before the third trimester the baby doesn't have a brain and isn't really alive at all. At around that point however the brain develops and there is some things that show it might feel pain and what not. So if you are going to draw a line where the baby might actually be alive, it should probably be around the time it has a functioning brain.

I don't really feel comfortable with abortions, but I also don't feel comfortable telling people they should ruin their lives for the next 20 years either. As for telling people they should never ever have sex, even while using protection, that doesn't realistically work out.

People say just don't have sex, and they its because they are thinking young people who are not ready but most abortions are done by older people who have children. So you are basically telling the 30 year old mother of two, that is married that she shouldn't have sex with her husband even if she is on the pill and he uses a condom because it isn't 100%.