I have just come across your post as have been searching on Google for an explanation to my sudden and very different erratic feelings and thoughts.
I'm 33 and never suffered from PMT, mood swings etc. my periods have always lasted 5 days and have been very manageable. But I had the copper coil fitted 3 weeks and 2 days ago.
I can definitely still feel it in me - not in a painful way, but it is uncomfortable. I have also been bleeding very heavily for 6 days (lighter for 3 days before also) and am using super super tampons every 2 hours. That's how heavy!
But the worst thing is, I've noticed went completely mental, irratic, irrational and paranoid for 3 days, starting the day before I started bleeding very heavily. I was so crazed, that I was convinced that my boyfriend had been up to all sorts. I was going to split up with him because of being so paranoid... I hardly ate anything and didn't sleep much I was in such a state!
I've heard PMT affects woman's hormones and moods, but have always been super lucky not to suffer at all from this - I got the copper coil to avoid the hormones.
So I don't know what's going on? I have my 6 week check up in just over 2 weeks so am going to stick it out and will come back to you.
At least I have my own head back on my shoulders now, but am still very heavily bleeding with no sign of it stopping and I can still feel it in there...