Translation doubt

Hi guys, a doubt came to me when I was watching a movie. I'm not sure the difference between this these two sentences:

"I would have thought I was going to die" (Habría pensado que iba a morir)

"I had thought I was going to die" (hubiera pensado que iba a morir)

Are ok these translations OK? In this case, can anyone explain in which contexts I should use them?

Thanks

I had thought = yo había pensado (The past perfect tense (e.g., había viajado) views an action or state as having occurred —and been completed— at a time prior to another past action, state or time.)

I'm not a native Spanish speaker, but I think that "hubiera pensado que iba a morir" would be translated as "I would have thought I was going to die" (as a stand alone sentence) unless it is part of a dependent clause such as "Me sorprendió que (usted) hubiera pensado que iba a morir" which would then be translated "I was surprised that you had thought you were going to die".  In this case el pluscuamperfecto de subjuntivo is also  used to indicate an action or state that occurred prior to something in the past.

Maybe a bilingual native speaker can clarify this further.