IUD (liletta) my period hasn't left it's been over a week!!!

So I got my IUD (liletta ) in December of 2016.... got my period on the 11tg of January 2017... it started off light like normal and hasn't left😖 it's the freaking 31st! I have cramps every now and then. No I cannot feel the strings. I called my doctors office like a week ago..and my MA said that the strings soften over time so that's probably why I didn't feel them and she said bleeding this long was normal that it gets lighter with each month. I'm starting to freak out, feels like I've been bleeding forever!!! I'm tired of it. Anyone else had this going on when they first got their IUD?