Latest Thursday I had mirena removed and they inserted nuvaring. I had no spotting or cramping until Saturday night. I have on and off light spotting since. This evening I went to the bathroom and had HEAVY bleeding with large clots (sorry tmi).  I am soaking a super tampon in 15 mins. I called my doc and they don't seem too worried. Has anyone else experienced this? I have abdominal and pelvic cramps as well as lower back pain.