I HATE MY....... parents????

THEY are sooooooo mean! Just because my sister got pregnant they are blaming it on me! I have a BF now and I am soooo ready to move in with him! He lives under my floor of the penthouse we live in. We live on the top floor he lives in the floor below us. It is only him and his brother. So it should be alright. I am not going to turn into my skanky sister and knocked up by him! We haven't even kissed yet! But my sis is 14, I am a responsible 13 year old. I am grounded over what happened with her. My 'rents we all like "Oh my goodness, Tianna your pregnant?! Oh and surley you told your sister and she neglected to tell us! SHE IS SOOO GROUNDED!" Should I move out? If not what other options do I have?