yes you will spot your doctor should have told you that.
You should experience some minor spotting for the first 6 months of having the IUD. Usually the spotting happens with the copper IUD. However with the Mirena IUD some women might not get a period at all. If your spotting is heavier than usual or you have scary bleeding and pain, go to DR.
I had a copper IUD taken out after 2 years, I loved it but I did spot every once in a while. I took it out to try to get pregnant. I will use it again after children