I Haven't Had A "real" Period In Almost Four Years

I haven't had a "real" period in almost four years on Mirena. My boyfriend and I had rough sex with toys we've never used before (rubber dildos if it must be known) and the day after I had cramping worse than up my usual cycle and brown discharge. When I do any kind of exercise it becomes heavier. I don't usually get real periods, but cycles with small symptoms of periods, but no blood. Did I scratch something or move something during sex that may be causing this?