That will always be a fair question to ponder but let me suggest asking that question from an assumptive position.
What are the odds of other life in the universe ever crossing paths in time and location with life on earth?
Consider that all locations in space are virtually empty and distance is measured in time at the rate of six trillion miles per earth year. The odds that different lives in the universe would cross paths and be within 10-100 million years of each other in time approaches infinity.
"R" is the rate of star formation.
"fs" is the fraction of stars that are suitable suns for planetary systems.
"fp" is the number of suitable suns with planetary systems.
"ne" is the mean number of planets that are located within the Continuously Habitable Zone (the zone in a planetary system, where liquid water is possible,assuming liquid water is necessary for life)
"fl" is the fraction of such planets on which life actually originates.
"fi" represents the fraction of such planets on which, after the origin of life, some form of intelligence arises.
"fc" is the fraction of such intelligent species that develop the ability and desire to communicate with other civilizations (they construct radio telescopes or laser systems, etc.)
"L" is the mean lifetime (in years) of a communicative civilization (it doesn't blow itself up or dies off for some reason.
In short, after all is said and done the answer can easily be zero.