It could all be due to the Mirena.

It is possible to get pregnant, but unlikely. You can still take a pregnancy test if you suspect pregnancy.

I know every woman who has heard or has used Mirena says it's so unusual to get pregnant on it. NO I do not believe that I have read hundreds and thousands of posts all over the net about women getting pregnant on this Mirena, which yes I have it and thought I was pregnant because I had all the symptoms. Now I have brown blood coming out and haven't had my period or spotting in YEARS. Also horrible headaches, white/clear discharge with blood in the MIDDLE. I am going to get checked tomorrow.

i am also having some of those same side effects. i am also going to get checked out too. i have been experiencing headache, loss of appitite, mood swings, no desire to have sex, cramping, brown discharge,and i haven't had a period in almost a yr. I've been thinking about having it removed but i don't know what to do. everyone i talk too says to have it checked out but i feel like i'm over reacting, am I? i also somehow have lost over 10lbs but my stomach is bulging out, i took a pregnancy test and it was neg. and advice.