Mirena IUD

I got the mirena inserted on 09/12, bled for a week. had a regular period in the middle of october, and now i’m 12 days late. i’ve had PMS symptoms for sure, just no blood or spotting. the last time i had unprotected sex was on 10/28.

i read that periods can disappear, but wouldn’t expect that to happen this early. chances of pregnancy are slim, but possible. does it sound like that’s what’s going on, or could i be pregnant?