Period, PMS, & Cramps Return After 3 Years on Mirena?

I had my Mirena inserted almost 3 years ago and my periods pretty much stopped after a few months. My monthly period has been just a couple of days of a bit of brown spotting since then. About 4-6 months ago I started to notice red spottting instead.

One night last month, I was in so much pain...it was so familiar but couldn't place what it was...it took me almost 24 hours to realize I was having menstrual cramps! It had been so long that I forgot what they felt like!

Then, this past weekend, I had a serious case of PMS. I was frustrated (for no good reason) and to keep myself from jumping at my husband and kids anymore I went to my father's house where I sat on the floor and cried for a half hour. (I used to get that way before I was ever on any sort of birth control.) Got my period the next day. Been bleeding since then. Not heavy but not like like it was last year either. I change my panty liner twice a day and when I wipe after urinating, it takes a good 3-4 wipes before the toilet paper is clean of blood.

I know I am supposed to check the placement of my Mirena once a month but I have never been able to feel the strings. My husband, on the other hand is EXTREMELY aware of it and tells me it's still there.
Don't know if this matters or not but:
I was considering having it removed originally because every time we tried to have sex he had to stop midway due to being "stabbed" by the strings. The doc said to give the strings a chance to soften and see if things got better for him. Although he said they did slightly soften, he has found that at a certain angle, the strings don't bother him so much and would rather keep the Mirena than risk pregnancy. The pill is not an option for me so Mirena is a lifesaver.

Any help? I've read about others who have had red spotting begin to re-occur but what about cramps and PMS? And all at once? What's going on?