Unfortunately this isn't an added chapter, and I doubt that I will write more for this story (though I have plans for SNR to get back in the swing). However, since the question has arisen several times, I thought it might be prudent to offer up an explanation of how the first chapter works.
Firstly, all that which is written in the italics at the start of the story is from Raven's vision; what she saw while she was meditating in 'present time'. The following, which is not italicised, is Raven in the 'present time', looking back on her vision in the company of Starfire, for the most part.
Secondly; How can Raven not know who the father of her child is? Simple – in the vision, she was not shown who the father was. There was nothing in her vision that told her who the father was, because none of Vision-Raven's thoughts were directed towards who had fathered her child. They were originally about how her pregnancy had changed the attitudes of her friends and her powers, and then, how distressed she was at being trapped in a beanbag.
Visions are fickle things; what one is or isn't shown won't be the whole story, but pieces of it. Raven was shown just enough of her future to avoid being trapped with a full bladder in a beanbag, should she take the precautions. Not enough to avoid falling pregnant in the first place ;)
Hope that helps some!