Well, depends if you are pregnant or you arnt,
if you arnt pregnant. then, safe sex or no sex at all :L
or if you are married, talk to your husband about getting a vasectomy. or consider getting your tubes tied.
If you are pregnant, then condsider an abortion, or consult your doctor.
abortion or abortion pill.
First of all, make sure you really wanna do this. There is no turning back. But if you're sure you wanna do this, go to the hospital. They'll ask you some questions. You'll need to explain why you wanna do it. They will determine how long you've been pregnant, and depending on how long, they will give you the options. There are many ways to have an abortion! you can't be pregnant for longer then 12 weeks though if you want an abortion. You really should consult a doctor on this though. good luck!
Christian answer: Have the baby.