Need help telling my parents about being pregnant please help me!!?

I posted about this before how I'm 12 and he's 19 and he got me pregnant well theres one huge kind of sick problem. . . He's my 19 year old stepbrother I feel ashamed of myself for what we've done, and now I'm pregnant and I don't have the heart to tell my mother and stepfather about us. And if I do theyll throw him in jail which I would hate them for it because I really love him and he loves me! What should I do!? Should I just have my boyfriend/stepbrother take me to go get an abortion?! Please help