Heavy bleeding and cramping

I got the IUD about 3 weeks ago now. I had zero cramps and felt great, up until the 2 week mark. After 2 weeks I started to get cramps that were unbearable, felt nauseous and couldn’t stand up. Almost like the pain when I got it inserted. I got my period on the 2nd and since then the bleeding has been nonstop and extremely heavy. I bled through a pad overnight and have not stopped bleeding, and I have bad pains. Is there a complication, should I go see someone ? The pharmacist mentioned severe cramps 2 weeks in is abnormal to have...