Megan Fox had a lot of fun last week teasing the Internet about who may or may not be the father of her unborn child — not Shia LaBeouf, she was quick to clear up — but it looks like the fun's all over.

And it further looks like our first assumption was right along: The father is none other than Fox's estranged husband, Brian Austin Green — which is awkward since they filed for divorce back in August and all. But anyway.

People magazine caught up with Green at a celebrity auto-racing event, and he couldn't hide his excitement — and terror — at being on the road to new dad-hood once again. "You know, nothing is planned," he said. "None of them are ever planned. You kind of just go with it. At my age, to be having three babies, is crazy. I'll be 43 this year."

As for that divorce? Not so fast. "This pregnancy was not planned, but when they found out they were extremely happy," a source tells E! News. "Megan and Brian love being parents. They are working really hard to be together and one unit—not only for their children, but also for each other. They are looking forward for the arrival of their new baby."