Linea Negra

You know that line that pregnant women get on their bellies? I looked on Wikipedia and the correct name is the linea negra. I had a pretty pronounced linea negra with Nora, but for some reason, I don't have one with Liam. Any ideas why? Did any of you guys have inconsistencies like this when pregnant? I tend to think that it's because this time is a boy and the hormones are all involved, but who knows? Just thought I'd put that out there in case their are any medical genuises who read this silly blog.