iud problems

So i just got my first iud placed about 2 to 3 weels ago for endometriosis and just recently i started to experience extreme cramps that feel like something is stabbing me and is squezzing really hard and i just started to have very very pale blood and i was wondering if its normal to experience this type of pain because of the implant or if it has moved or gotten infected. And yes i have called my doctors office but the nurse that aswers the phone just tells me to take some ibuprofen and use a heating pad when i have been but it has done nothing. Now keep in mind that this nurse also told me that my belly button incision wasnt infected because the pus wasnt green or smelly.