I did not get my period until about 7 weeks post mirena. and the night before getting it i had the same deep painful side effects and muscle and chest pains, i wanted to go to the emergancy room i didnt know what was happening, the next day i had gotten a very very heavy period, it did take 7 to 8 weeks for me to finally get my periode, and i didnt have it in years, so i definatly felt the way you did, even a hot flash. i am 28 so i am almost your age , i thought i was gonna go through early menopause, but i wouldnt worry, and if you had yours in a year longer than i did you might need a little more time to get your period i am sure you will get it, i ended up getting it unexpectedly.