I Have A Mirena Coil And Do Not Come On

I have a Mirena coil and do not come on at all - it's been 3.5 years since I last experienced menstrual bleeding. However, this past week, I flew 3 times on a business trip. My first night home, my husband and I had sex, and afterwards I bled heavily for 1 day - this wasn't a pale pink show, this was deep red, and clotting, with some cramping and felt under the weather. Could this be related to flying?