There's a lot of speculation in this thread, based on very little information.
Assuming the story is true, I congratulate mother and father and add a prayer for a healthy pregnancy and baby.
In general, I think that TB is entitled to some privacy in this regard, but, since he lives a fairly public life with some highly visible women, he can't expect complete privacy. He's entitled to a respectful discussion of what this might mean for his team but he can't expect there to be silence on the subject.
As for whether this will be a distraction for him, of course it will be a distraction. We just don't know how much of a distraction. Ultimately, his teammates and coaches will be the only ones to decide whether it interferes with what he delivers on the field, and I suspect they will let him know in no uncertain terms if they think he isn't practicing or performing up to their expectations based on their knowledge of his ability.
Tom Brady has already delivered three championshiops for the Patriots and their fans--more than all but a very small handful of the thousands of Quarterbacks who have ever played his position have ever delivered for their teams. He is entitled to chart the future course of his life on his own terms.