Paragard IUD & late period

Hey Ladies. I've had the paragard IUD for almost 3 years now. Been a bit irresponsible lately with checking for it after periods. Didn't think anything of it to be honest. But this month my breasts have been extremely sore for about a week. Thought maybe i was getting a new "pre-period" symptom since period was due on December 16th-17th. I've never had sore breasts as a sign of period before, but our bodies change so why not? Lol

Well anyways, today i should be coming off my period. But i haven't even started yet. So out of concern both my boyfriend and i tried to see if we could feel the IUD, but we cant find it. Kinda freaking out because we're not ready for a 4th kid. Any advice? Or any simular stories? Thanks.