Linea nigra: When does the pregnant belly line appear and why?

What is Linea Nigra? Your Pregnancy Belly Line Explained

Hello some one told me this line was a linea nigra which I've read

Linea Nigra: Learn About the Pregnancy Belly Line

How Does Skin Change During Pregnancy?

Anyone who has tips on how to get rid of the linea nigra? Also

Pregnancy And Skin: What To Know About Linea Nigra And Its Causes

When Does Linea Nigra Appear?, Linea Nigra Pregnancy

linea nigra at 9 weeks ?! - 1st Pregnancy, Forums

Linea Nigra: Everything You Need to Know