Random heavy bleeding

Ive have the mirena IUD for around a year or two. i had super irregular periods and spotting nonstop for the first few months of using it, but for the past 6 months i’ve has a very regular and steady and usually really light periods. I started my period at the beginning of this month and it ended around 5 days ago. Today i was at work and felt something come out and i went to the bathroom and there was an insane amount of blood all over.. it even went through my jeans which has never happened to me before so i was really surprised. my period has been done and i’ve never bled this heavy especially nkt all at once. i also don’t have any cramps or any period symptoms at all. just wondering if anyone else has experienced this or know what’s going on?