Rebecca's pregnancy at the beginning

At the beginning, when Rebecca is sitting on the porch at the beach house rubbing her belly, is she pregnant with Tommy2 or with Tommy2's baby?

At first I assumed that this was her pregnancy with Tommy2 but now in retrospect I think otherwise. She says "It's over. I will always speak to you. And I don't mind if you don't say anything. Just because you went away, it doesn't mean you're not here anymore. Perhaps all I ever needed was this gift. The one you gave to me at the end." To me, that resonates way more when you think of her having lost a man who she'd gone through 30+ years with rather than just someone she met as a kid and dated for a short while before he died. Also, they did have unprotected sex just before he left, and she's still young enough to get pregnant. As well, would she say "it's over" if she was carrying the clone of her lover in the hopes of continuing their relationship? In that case, she would probably not believe it was over. But when Tommy2 leaves it IS well and truly over. And finally, I just think it makes more sense from a storytelling point of view to have the opening scene be something from the end of the story, reflecting on all the events, rather than something that happens midway through.

Anyone else think this or am I making a giant stretch here?