What Causes Severe Cramping With Bleeding After Intercourse?

I have a mirena IUD, have had it now 2 1/2 years. Recently, I started experiencing severe cramping after sex, and moderate cramping during day to day activities (such as work, cleaning, etc). I have not had a period since insertion, just spotting now and then. However, there is light bleeding accompanying the cramping. Could this be a sign of perforation or embedding?