Dear user, welcome to healthcare magic.
implant is the most effective reversible contraception
, still there is a failure rate.
One in one thousand gets fregnant after one year and seven in one thousand get pregnant after five years of mirena use.
There is always a chance of pregnancy
even after bilateral tubal ligation
In any menstrual irregularity pregnancy must be excluded by a blood test
The symptoms you mention are non specific and non conclusive.
I suggest you have a blood test for pregnancy to cut short your confusion. If the test is negative (my expectation), so consider these symptoms a temporary side effect of mirena.
Dr. Ahmed Bahaa.