Jabba,
I'm sorry to tell you that such a likelihood is impossible to calculate. The problem is that we have no idea how many universes have existed "before" ours - how many were too small and collapsed, how many were too big and completely came apart, how many had fatal flaws in their maths that led (like a fetus with a mutation) to their early demise.
If the chance that sentient life might somewhere exist at some time was only 1 in 1,000,000,000,000, that information would be of very little use if this is the 100,000,000,000,000,000,000,000 universe to exist. In fact, the chance of this universe coming into existence approaches 1.
So, I apologize for not being able to follow your hypothetical. There's simply too little information to begin to create a probability - either very small or nearly certain.