i am late in my period and took pregnancy and they said negative, i went to the doctor and he says that i'm fine becuause i have the iud for almost 3 years that it's still there i asked him why i'm late all he said was that i should still be getting it but nothing yet it is already a month and it is almost 2 months. I am feeling tired easily, have headache that come and go, have sharp back pain and stomach and also adominal what does it mean.