Yes you can. All states allow abortion in the second trimester and how far depends on where you live.
By a surgical abortion. It's legal in all states.
If your already pregnant and have sexual intercourse during anytime of your pregnancy you can not get pregnant.
some do and some don't
By a surgical abortion using a method called Dilation and Evacuation, a D&E. They slowly open the cervix and remove the fetus using tools.