Week after Mirena; can’t feel strings & spotting after unprotected sex?

Hi, my Mirena iud was placed on a Friday, and my doctor told me to wait a week before I have unprotected sex and to use a backup birth control for that week as well. I waited about 8 days to be safe, & I had unprotected sex that Saturday morning. For the rest of the weekend I was having unprotected sex. I would also mention that I had rough sex at some points too. Last night I had very bad cramps in my pelvic area that were almost unbearable, I took a painkiller and went to bed. No cramps today, but I did notice I am spotting light red blood. Even though I waited within the guidelines my doctor gave me, I do fear that I may be pregnant, or my IUD has fallen out of place. I also tried to check and see if my IUD is in place, but I couldn’t feel the strings. I did read something about the cervix being dilated and women were unable to feel their strings, and it said to check back around my next period.

Any help? Thanks