I'm posted so much about Mirena I am going anonymous for this post. I got the Mirena placed 5 days ago. I know that if you have it put in during your period it is immediately effective. However, it's different with me. I have been super irregular the last few months. Bleeding two weeks at a time and now I've not bled for over a month; I'm not pregnant. Therefore I had the Mirena placed some other time in my cycle and I have no clue where I'm at in it at this point. My boobs aren't sore or anything, and discharge is minimal. I feel like I'm not ovulating but hell, I don't know.