first thing you need to do is calm down and find out if you really are pregnant. You need to find someone you can trust and talk to them about it. Whether it's your boyfriend or a friend. Preferribly an adult. Like a teacher, older sibling, school nurse, or an older relative. I had the same thing happen to me when i was 15. I told one of my friends that i thought i was pregnant. She told her mother, who called my school and pretended to be my mom. She took me to famliy planning (which is like planned parenthood) and i got a pregnancy test. Turned out i wasn't pregnant.
Once you know for sure (and if you are), then you should tell your parents. I know it's scary to tell them but you have to. Your not a little kid any more. It's something you have to do. And they can't kick you out. They will probably be disapointed and it may seem like they're mad. But your their baby and they love you no matter what.
But if they do get mad (like mine did when i got pregnant at 17) and try to make you have an abortion. DON'T LET THEM!!! You have the right to NOT have one. Fight for it. If they drag to get one done tell a nurse.
Hope this helps. I hope things work out for you!