No period for two months...

Kate • Mirena user 🇨🇦
I got the Mirena IUD in July, and was having my period as normal (though a little longer and heavier than usual). Now, for the last two months, I haven't had any bleeding at all. I haven't even had pms. 
Is this usual? Has anyone else experienced this so soon aftergetting their   IUD? Could I be pregnant?
I am an expat in China, so tests are not easy to get my hands on...