Good afternoon doctors I was diagnoed with PCOD last month through abdominal USG. From last few days I noticed linea nigra on my stomach which is a common sign of pregnancy. But I cannot be pregnant as 1. I never had  penetrative intercourse, only external activities and that also with condom always. No sperm involved 2. I am having regular monthly periods and never missed a period, even this month i had my period 5 days ago 3. Did 3 b hcg which is negative 4. Did 10 upt which were negative 5. Even adominal USG showed no sign of pregnancy. Then why i am having linea nigra. I am really stressed and scared of being pregnant.. Please help.