YOU SAID:

I went to 7th period at 2:00

INTO JAPANESE

2時に7時間目に行きました

BACK INTO ENGLISH

I went to the seventh hour at 2 o'clock.

INTO JAPANESE

私は2時に7時間目に行きました。

BACK INTO ENGLISH

I went in for the seventh hour at two o'clock.

INTO JAPANESE

私は2時に7時間目に入りました。

BACK INTO ENGLISH

I started the seventh period at 2 o'clock.

INTO JAPANESE

2時に7時間目の授業が始まりました。

BACK INTO ENGLISH

The seventh class started at 2 o'clock.

INTO JAPANESE

7番目の授業は2時に始まりました。

BACK INTO ENGLISH

The seventh lesson started at 2 o'clock.

INTO JAPANESE

7回目の授業は2時に始まりました。

BACK INTO ENGLISH

The seventh lesson started at 2 o'clock.