Bleeding and Cramping After Pilates

Curious if anyone has experienced cramping and bleeding after working out? I had an IUD placed in Jan and continue to have random bleeding. Can't really tell when it's a full on period. Anyways it has been twice now (with breaks in between) that I cramp and bleed the day after 10-15 minute of Pilates and it lasts for days! Sometimes it's accompanied with un-cramp like pelvic pain. I do have an appointment schedule with the doctor already.