What Causes Pain In Lower Tailbone Area?

I have been having pain in my lower tailbone area upper butt area and sides. It hurts when i sit, stand, lean down, and when i pick up my kids. I have Mirena and people have said it could just be cysts, but this is a constant pain. I had started working out about a month ago on my Wii Fit and thats when the upper butt pain had started but my back pain has been like this for about 2 months now. what can be causing this pain?