translation - Meaning of 〜たら in this sentence

Sorry if something similar has already been asked, but I can't seem to get my head round translating this sentence.

• 好きな人に告白したら、サインを貰いました。(This comes from a manga xD)

I get the gist of the sentence, in that it means something like "I confessed to the person I like, but I received his signature instead" or "Even though I confessed to the person I like, I received his signature instead". Any idea on how to interpret the use of 〜たら here? Because I don't think that's a conditional sentence...

Thanks :)