I had the mirena (levonorgestrel) put in about 2 years ago so why all of a sudden I be on my period when I never had one before bleeding

Common. The number one side effect of Mirena (levonorgestrel) is irregular and unpredictable bleeding. For some women it starts right after the device is placed in the uterus. For others, like you, it starts weeks, months, or years later. It is possible to have some other cause for the bleeding, so it would be wise to see your doctor for an exam and possibly an ultrasound to evaluate for other problems or causes.
Few . Few possibilities: pregnancy, the Mirena (levonorgestrel) has been expelled or migrated, you can still have periods with the Mirena (levonorgestrel) in place. Perhaps you were not ovulating for the past two years and have recently started to ovulate. I recommend a pregnancy test and probably an ultrasound to check the location of the iud.