It's likely just your mons pubis...which is the area your referring to. Some women have a puffy look and others dont. It's just genetics. Mine is like that too. As your grow it won't be so noticable.
If it's new, it is more than likely just from being irritated. If you don't have any other symptoms, I wouldn't worry about it. Mine does the same thing if I use perfumey soaps or detergents. Wear loose clothes and let it breathe and avoid washing it with strongly scented soaps if you can. :)
Hi there. Is it new? Swollen or just the way you are?