Hi Sara
I don't know the answer to your question, but I too have a Mirena. My BGs stay pretty much the same but I was diagnosed a while after having the Mirena put in and haven't had it changed yet.
Hopefully someone may come along with a bit more knowledge. Don't know what's the worse proposition .... High Blood Sugars or NO MIRENA :shock: Don't know if I could go back to my pre Mirena hell !!!
Of course, sugars can be all over the place for various reasons, not just food related. It may be that you've been fighting infection/viruses or are a little run down, or something.
Hoping we both find out more!
Cath x