Not had heroin 2 months came back positive?

Heroin is made from scrapings of the opium poppy. This is the same type of plant that your regular household poppy seeds come from. When both heroin as the simple seeds get processed through the body, they break down in certain other chemicals. These 'metabolites' are similar in structure and are very hard to distinguish from each other. That's why it is possible for someone to have a positive test for heroin after eating poppy seeds or drinking poppy tea.