Weird period


I've been bleeding on and off for about two weeks, started normal and then got heavy and have been having a lot of abdominal and back pain, which is pretty unusual, especially in my lower right side. Just when i think the bleeding is over, when I have sex there's more blood. I have an appt Friday to see what's going on but has anyone experienced anything similar and know what was going on? Last baby was a year ago and have been on mirena since with no issues until now.