Period & Mirena way TMI

Ok, so I had the mirena put in a few weeks back. I had the normal spotting, cramping and pain for a few days, then it was fine. Every few days or so, I have a major break through type bleeding that only lasts a few hours. Now today, I started cramping when I woke up. It may be time for an actual period, but I wouldn't know since my previous birth control had me bleed for months straight. Anyway, now I keep having pains pretty similar to when I was in labor with DS and clots just keep coming out. (TMI part I warned about) They are rather large, and I don't know of this is normal? Considering I have bled so much these last few months, I just dont see how I could have that many clots. Has anyone else whose had mirena experienced this? I have an appointment on the 30th to have placement checked, but I am wondering if I should go in sooner? Any advice is appreciated.