Confusing symptoms

My cycle is usually 2 to 3 days in length. It ended 6 days ago. I started getting backaches and cramps in my abdomen with heavy spotting. Is this a sign of ovulation or something else because I haven't had this problem before . We've been trying to conceive since I had my Mirina removed back in October. I'm not sure how to feel about the bleeding/cramps....I haven't had this happen after a cycle ends and it's been 2 days so far since it started. Any ideas?