YOU SAID:

You would've never guessed that this certain thing happened to me

INTO JAPANESE

こんな事が私に起こったなんて、君は決して推測しなかっただろう

BACK INTO ENGLISH

You would never have guessed that this had happened to me.

INTO JAPANESE

こんなことが私に起こったなんて、君は決して思いもよらなかっただろう。

BACK INTO ENGLISH

It never occurred to you that this had happened to me.

INTO JAPANESE

こんなことが私に起こったなんて君には思いもよらなかった。

BACK INTO ENGLISH

It never occurred to you that this had happened to me.