IUD Trouble?

Got my Mirena on 4/9 on day 4 out of 5 of my period. Everything has been pretty much okay until last night. I wasn’t supposed to start my period until 5/7 but I think it came last night. It’s super heavy & I keep getting this very sharp pinching pain in my uterus area along with cramps. I’m bleeding pretty heavily. My OB/GYN’s office is closed today so I can’t call her to ask what’s going on. Is this normal?