Sorry to disappoint you but I think the chances are quite low. Here's why -
As Neil deGrasse Tyson puts it - 'when is the last time you stopped and had a conversation with a worm'? Chimps share 95-98% of our DNA and yet we cannot really understand their ways and to be honest, most of us don't really care.
So if there really are aliens who have discovered us, they must be much more intelligent than what we are. In that case, why would they even bother to communicate with us? We are nothing but what worms are to us. Probably, all they might be doing now is studying us.
- The 11 dimensions:
We as humans can see only 3 dimensions and are woven into a 4th one - time. However, M-theory suggests that there are 11 dimensions in all! So it is highly probable that these life forms we are seeking maybe existing in a dimension we cannot sense.
If you have a lot of time in hand, check out this long series which explains everything.
- What is a life form anyway?
The general view about a life form is that it needs nutrition, water and air. Now we know nutrition can be different things for different creatures. Moreover, scientists have now discovered that there are creatures on Earth itself that don't need oxygen to survive.
In that case, how do we define what an organism is? In a possible scenario, we may have already come across living organisms made up of chemical compositions in outer space which we have plainly dismissed as galactic clouds or something. Sam Neill wants you to think like that too :)
In the light of those arguments, common sense would dictate that we will probably never be contacted. However, we do know that life does exist somewhere in some form out there and that it is up to us to contact them instead.