Thanks for your query at DoctorSpring.
On the Mirena Coil, it is typical not to menstruate, or to have periods very scantily, if at all.
The other symptoms that you describe, could be pre menstrual symptoms. They could be attributed to the hormonal effect of Mirena also, but you have had it for 3 years, so you would know if you had them earlier too. On the other hand, pregnancy is a rare possibility also.
Please take a pregnancy test, and if you do not have a proper period, or the symptoms do not subside in a few days, please report to your doctor.
Please take care, and do write back if you have any further questions.