YOU SAID:

my father is pregnant and i'm the sister

INTO JAPANESE

私の父は妊娠していると私は妹です

BACK INTO ENGLISH

My father is pregnant and I am a sister

INTO JAPANESE

私の父は妊娠しており、私は姉です

BACK INTO ENGLISH

My father is pregnant and I am my sister

INTO JAPANESE

私の父は妊娠しており、私は私の妹です

BACK INTO ENGLISH

My father is pregnant and I am my sister