Can birthcontrol kill the fetus and end pregnancy even if the girl has been pregnant for about a month or 2 weeks?

Why are you asking that kind of a question?

I don't think regular birth control has the power to do what you are asking. There is, however, a pill which can be taken to terminate the pregnancy. It's commonly known as the "abortion pill", or RU486. It can only be administered by a doctor or clinic. From what I understand it is a horribly painful experience for many women, leaving them essentially crippled in pain for 8 to 12 hours.

The Abortion Pill: Mifepristone and Misoprostol for Early Abortion

No it does not.

No, I was on birth control pills when I found out I was pregnant.