So confused! Please help

Whyyy would I be 17 days late?! I've taken pregnancy tests (been practicing safe sex and not ttc at all) and they're all negative but I still haven't started. Nothing has changed except I got my mirena out about 3 months ago because it imbedded itself in my cervix. Had one weird period right after removal and one what I thought was a normal period a couple days after my expected start date. Any experience/advice/knowledge?