I had Mirena put in 4 weeks after a miscarriage and was checked for both STDs beforehand (negative, of course) and did not have any sex in the 5 days between the time I had it placed and me ending up in the emergency room. In fact, I hadn't had sex for weeks as I'm in a long-distance relationship so I DEFINITELY did not bone anyone during this time or any time recently.
The pain only got REALLY bad on the 4th day; up until that point, I was conscious of "something" there and my lower back ached similar to how it did when I was in the process of the Master-Cleanse but worse by the 4th day after insertion. Something was not right and I should have listened to that voice telling me that. To any women reading this because you are Googling the symptoms right now: you have that voice for a reason, respect it as it is trying to help you.
Anyway, I spoke to the doctor that day as they were checking in to give me an HCG update (it's dropped very slowly since the MC, something that gave me pause about getting fitted with an IUD so soon but they insisted everything was cool) and asked if it was normal to be hunched over when I'm washing my face and feeling significant lower back pain after insertion. She said yes, hang in there, it's worth it, etc etc. Really? Like hunched over at the mirror hurting? That seemed odd to me but OK, it seemed they knew what they were doing.
By day 5, I could not take it. Tears were streaming down my cheeks and I was at work unable to leave for 13 hours. I called the doctor again to get a prescription called in (Ibuprofen leftover from the Master-Cleanse were not working even though I was eating them like candy) and she refused saying if it was that bad, I needed to come to the ER. I told her I could feel the strings so it hadn't slipped, I was stuck at work and just needed something to get me through the next 13 hours so I could go to the ER after. She refused, I went back and squirmed through the rest of my day, drove home exhausted and fell asleep.
I woke up the next morning in some of the WORST pain of my life. I've had a child. I just had a miscarriage. I have tattoos. I know pain and am kind of a wuss but this f^%&ing hurt. I called the doc again crying and said I'd be coming in to the ER.
They didn't hesitate to pull it - and as a matter of fact, my ER doc actually had one herself (she said it took her 3 months to "get used to it" and now she loves it - to each her own). They gave me a shot of dilaudid (presumably so I'd stop howling and crying, this was an embarrassing production) and came to take it out.
My ER doc seemed to want to write it off as "rejection" of the device somehow but her attending (it's a county hospital, good times!) wanted to say it was PID because "my pelvis WAS technically inflamed". They gave me Antibiotics , called it PID and sent me home. I was better within a day, though now I still feel "traumatized" and the lower back pain is constant but tolerable. I went for a follow up 48 hours later and even that doctor thought the PID diagnosis was strange. "You SURE you haven't had sex since you had it put in?" Trust me, lady, I haven't gotten any. And even if the opportunity had been there I wouldn't have wanted him to touch me, the thing made me feel awful from day 2.
So does it cause chlamydia? Not exactly. I know I've never had anything like this in my life and it wasn't my boyfriend who gave it to me so how do you explain that? I feel like my uterus has just been in a swordfight and lost. They say the risk of infection during or in the 20 days after insertion is SMALL but somehow I am the .0000001% who it happened to even though I take great care of my girl parts, especially after the MC.
The whole time all I could hear from my body was "GET THIS THING OUT" and maybe I somehow created a psychosomatic infection. That explanation seems unlikely so my best guess is that for some women, your body just refuses whatever the hell is in this evil thing. It seems from what I've read on forums like this that it can happen right away (like it did with me) or after 1 - 2 years, there's no pattern to it and that's what frightens me about Mirena. I'm glad I didn't try to suffer through it because "it gets better" and "it's worth it!" because if I couldn't make it 5 days, how bad would it have gotten a year or two later?!
Nothing was worth was I went through. That's just my opinion. My uterus agrees with me.