brown smelly discharge AGGHAGAHHAGHA!!!;;!;

so I got the IUD a few weeks ago and I've been bleeding and whatnot and I noticed the bleeding has died down but now I have this weird brownish and smelly discharge. could this be from the IUD? It stains all of my underwear and it smells funky and I don't know what to do. I'm going to the GYN tomorrow but I just want some advice