Liletta IUD

2 weeks ago I had the Liletta IUD put in. My doctor said it's similar to Mirena. I was on my period when it was inserted & my period stopped at the normal time. This past Saturday I started having red & brown discharge. It has a funky smell to it was well. I'm not able to wear tampons yet so have been using panty liners. I was just wondering if this was a normal thing & how long I should expect it to go on? I've read that this kind of discharge is similar to what can happen when someone is pregnant so I was just curious if this was my body responding to the hormones. I was on the pill for 9 year prior but took an almost 2 years hiatus from birth control so my body has to readjust. That's been the only thing that's happened, so far. Thanks for your help!