Please Tell Me This Isn’t Happening!

I am almost 11 months postpartum with my third child. Got the Paraguard IUD put in about 8 weeks PP. Got my first PP period in, I think August and since then, my cycles have been coming like clockwork. AF is 9 DAYS LATE!! Since high school, the only time my periods have been late is when I’ve been pregnant. Has anybody ever, or know anybody that has gotten pregnant with an IUD? What was the outcome? Should I take a pregnancy test or is there something else going on? Please help!