I believe some calculations put there like 15-16 thousand Civilizations out there.
Main issue is that they most likely are COMPLETELY alien, were not talking star trek aliens, were talking about eyes coming out of there mouth mounted testicles, they probably wouldn't even have feet, maybe not even mouths or even eyes. (Edit: Testicles are earthlike things aren't they? Remove them then.)
Not to mention Cultural differences... Oh gods the Christians would be horrified.
Even if they were able to get to earth, they'd be REALLY STUPID to make first contact.
I'd be within a year after first contact, at our current situation, we'd blow ourselves up.
nah they'd blow themselves up, face mounted testicles... *takes gun to head and pulls trigger*