Possible pregnancy on mirena iud?

I got my iud put in on March of last year, which means I just turned a year with my birth control. I would still get my periods after getting it inserted but around January I stopped getting my period .

My boobs are hurting, I have small cramps, & I feel a bit nauseous . Does anyone know or has gotten pregnant while being on a IUD? I can’t be pregnant.. not now.