YOU SAID:

I went to school and there was some girl in the bathroom screaming

INTO JAPANESE

学校に行ったら、バスルームに女の子が叫んでいた

BACK INTO ENGLISH

When I went to school, a girl was screaming in the bathroom

INTO JAPANESE

私が学校に行ったとき、女の子がトイレで叫んでいました

BACK INTO ENGLISH

The girl was screaming in the bathroom when I went to school

INTO JAPANESE

私が学校に行ったとき、女の子はトイレで叫んでいました

BACK INTO ENGLISH

The girl was screaming in the bathroom when I went to school