I jave a friend who uses heroin. She is almost 37 weeks pregnant. She uses maybe once a day and very little. She said she snorts it. She is concerned about quitting completely bc she doesn t want to hurt the baby via withdraws. She said thats the only reason she hasnt completely quit. But she is afraid they will take the baby away. How long would she have to not use for the doctors to no detect it in he baby when she is born.