You are a bit too much of a busybody concerned with the private life of teenagers, aren’t you?
I don't think so. Others may but I don't. There is an argument for getting married as early in the pregnancy as possible in order that the bride "not be showing" in her wedding dress. There is another school of thought that says if the wedding can't be early in the pregnancy, let it be after so that the bride is able to "get back into shape"
At this point, the birth date is near and for a wedding six months post-partum, plans should should start being made but apparently they aren't.