IUD Concerns and Questions

I've had my IUD for four years now. I've absolutely loved it I've had no issues with it. My periods had been very light and the with little to no blood or symptoms for the first 4 years. However I'm supposed to get it replaced in May (the 5 year mark). For the last 6 months I've had really terrible cramps and bleeding back to my previous IUD levels. 5 or 6 super tampons a day. I went to the doctor told them my issues the IUD is still in place (which is what the doctor was worried about). She said it does not decrease effectiveness over time and has no idea why I'm having these issues. Does anyone else know what's going on or have any suggestions it's getting ridiculous.