Board Thread:Character Discussion/@comment-28162607-20170103120839/@comment-91424-20170103132335

The writers of the show have never been very good with math, and yeah, there are quite a few holes in the show's timeline (I've pointed out all of them - I think - on my own timeline here). But as for when they met: The flashback in "There's No Place Like Home", which takes place on the same day where they first met in "Tallahassee", takes place in 2001, according to a title card. See this image. So they met in 2001, and Henry was born in the middle of August, indicating that he must have been conceived not long after they met.