What Causes Irregular Periods With Nausea And Cramping?

i have had irregular periods all my life but recently i have had one every two weeks with spotting and heavy flow i have had fatigue dissiness and cramping with back pain 3 years ago i have an iud put in so im pretty sure it isnt pregnancy ive also taken a pregnancy test to be sure also i have 2 abnormal papsmers in the last 2 years