I gave birth via c-section ten months ago when I had the c-section I got a uterus infection. When my baby was 2 months old I had the mirena put in and began having sex with my boyfriend. I began to have pain the first time we had sex after almost six months of this pain I had the mirena removed thinking this was what was causing my problem. The mirena has been out for almost two months now and it is still very painful to have sex

This is unlikely due to the Mirena - but when you have a c-section - you can have a lot of scar tissue what we call adhesions in the ob/gyn world - and this can cause you to have a lot of pelvic pain during intercourse.
Also, you might have an ovarian cyst, or possible an urinary tract problem too - so It is highly recommended that you get a pelvic exam, a pelvic ultrasound, and cultures too as you might have an infection.
I hope this helps, thank you