Is bleeding and cramp normal with the mirena coil in after a year of none at all ?

Ive had the mirena coil for nearly a year with no bleedin at all the whole time . This month ive had alot of pain down below and my bleedin has come back so iam unsure if this is normal or has my coil came out ??? I do however have only one ovary so i dont know if this could be to blame aswell ??