They won't ever go away- but they will fade with time and become silver looking. Some people sweat by cocoa butter and vitamin e to reduce their appearance.
They won't go away but, coconut oil helps them from not coming. I've been using that oil and I'm 36 weeks with no marks
Dream Belley butter is really good to help with sterch marks/ to soothe ur stretching skin
I always use cocoa butter as a body lotion even before I was pregnant. I have been using it for years. So far so stretch marks
Unfortunately, they won't go away no matter what you do. The good news is that cocoa butter with vitamin e when applied generously daily will make them fade to the point where they are barely noticeable.