Dark belly buttom while pregnand?

Linea negra (normal): This is normal - there is a line of connective tissue down the middle of the tummy, called the linea alba ("white line" in latin) when we are not pregnant. It becomes darker when it gets stretched during pregnancy, and is then called the linea negra ("black line"). Sometimes it can be seen down the whole belly, sometimes just at the navel. The darkness will fade again after the baby is born.