Is there a point where everyone in Judaism agrees you are not allowed to kill a fetus. That could 1,3 or 6 months.
Let me clarify: Judaism prohibits the killing of a fetus. This begins immediately from conception. Even the pill known as "plan B" is prohibited. However, Jewish law has a concept known as a "Heter".
A "Heter" is a special waiver (so to speak) for an individual to do something which is normally prohibited. For example, a person who is very ill may eat on Yom Kippur.
Because Jewish law doesn't see a fetus as an actual life, there are various cases in which one may receive a "Heter" to abort.
For example, a woman may receive a "heter" to use a plan B pill if she was raped.