mirena IUD can cause symptoms like pain, bloating sensation of the abdomen, nausea, dizziness
, mood changes, amenorrhea
so your symptoms could be possibly because of the IUD,
as the IUD is having some amount of failure rate we cannot completely rule out the possibility of pregnancy
so this time when you consult your doctor with his advice you can go for blood test
for pregnancy which will rule out the possibility of pregnancy,
usually the symptoms will subside soon but if the symptoms become severe better to think regarding changing the type of IUD or to go for another method of contraception.