I really have no clue what they mean. A month or so before I got pregnant with this one I had a crazy dream about deliverying a baby girl in a parking lot. She was so beautiful and looked just like she was one of my kids, and I wasn't sad at all to have her instead of a boy. I even gave her a name. Could've been the baby I miscarried that was due around a month later?
But ever since getting pregnant all of my dreams have been about having a boy. I will know in 3 days whether my preconception dream was right or if it's been my pregnant dreams that are right.
Besides just the gender I like to look at what is happening in the actual dream to see if I'm supposed to get something out of it. I write down key points that happened then I find a dream dictionary online to interpet what those things mean. Usually it makes complete sense of how I'm feeling or what is going on in real life at that time. If there's nothing really going on that are signs, I take it as something that is to come for real (like the pre part of a de javu).