IUD period or pregnant ?

I just had my iud (mirena) put in on October 20th. I started my period that day and had a check up on November 17 that I didn’t go to because I felt the strings so I assumed the iud was still in place. I discovered last week (dec. 9) that I couldn’t find my strings anymore and that the iud possibly moved. I had to continually use the bathroom for the follow three days but I after that I was fine. Last night I started cramping and was bleeding a little bit but woke up this morning to find no cramps and the bleeding had stopped and turned to pink mucus. I am now currently 7 days late and don’t know what to think exactly. Any insight helps.