Hi, It would help to know how long have you been having Mirena and did the symptoms begin after insertion. Mirena contains a hormone that keeps on getting released slowly and protects against pregnancy. The use of this hormone has been associated with nausea, vomiting etc but it has not been reported much with Mirena. But still it is possible. Still you must get a pregnancy test done as pregnancy, though rare is still possible with Mirena use. Also try a to eat frequent small meals and light exercise to help with digestion. If it still persists see your doctor and get an evaluation done. Hope that was helpful.