Paragard IUD

I got my Paragard IUD January 2017 and for  the first two months everything was going great. My first period with it was normal, just a some cramping but that was bearable. I ended up missing my period in March and started spotting in April. Since then I've been bleeding non stop. The bleeding is heavier than spotting but lighter than a period and I get some discomfort on occasion (sometimes I swear I can feel my IUD). My doctor didn't know why I missed a period and haven't stopped bleeding either. Any similar experiences or advice?