What Causes Spotting And Odourless Discharge While IUD Have Been Inserted?

I have had my IUD for a little over 4 years now. I have always been able to feel my strings until recently. I have an appointment next tuesday for a pelvic exam since i didnt have any imediate pain. Is there a chance of pregnancy since i cannot feel the strings anymore? I have not had a period almost the whole time it has been in. A few weeks ago i had just a little bit of blood when i wiped for a few days and a lot of clear odorless discharge? I don't know if any of these thing have anything in common, but i would like a little more insite on everything since my apt. is still a week away.