on Mirena getting a lot of back pains, bleeding excessively

Hi,
Welcome to ehealthforum.
It is difficult to comment on the cause for the symptoms of back pain and prolonged/heavy bleeding that you describe without examining you. Consider visiting your treating gynecologist for follow-up evaluation to look for the underlying cause. Further investigations would be required to confirm the position of the IUD and rule out IUD related complications. Treatment as appropriate (based on the examination findings and investigation results) would be started to help you control the bleeding and regulate your periods. Be in regular follow-up and monitoring of your treating gynecologist and report any abnormal/new symptoms immediately. Take adequate rest. Drink plenty of water. Maintain healthy diet and lifestyle.
Take care.