Is dreaming about pregnancy a sign?
There are a lot of books on the market about dreams and their meaning. Stories have been passed down, even through tribes, about the meaning of dreams. I can't help but to debate if they have some meaning or another.
I think, moreso than dreams being some prophetic source, it is your minds way of processing and refreshing. Oftentimes your subconscious knows things before your conscious mind becomes aware (take the 'feeling' of someone watching you, for instance) so I do think that dreams can hold insight into what is happening in your life and maybe even provide answers, if you look closely enough.
I don't think, however, that it's going to be in form of dreaming about pregnancy. Dream signs are generally highly personal and one of the only ways that I'm aware. Dreaming about pregnancy is very, very common and likely means nothing or has some other symbolism in your life.
Dreaming about pregnancy is not a reliable way to determine if you are pregnant, and is probably not generally even a sign.