Is 'before' an adverb?

[Reenzia]

Hi there,
May I know if the word 'before' acts as an adverb in the following sentence? Thank you.

I woke up early and before I was out of bed, I noticed a small package on my bed.

[Alan]

No, it is a conjunction.

An adverbial use would be e.g.

I had seen her somewhere before.