Two books on hormones and understanding one's cycle that I think could REALLY help guide you are:
Taking Charge of Your Fertility (bad name, great book)
One of two books by Uzzi Reiss, MD: The Natural Superwoman or Natural Hormone Balance for Women.
Check them out...
Both are amazing resources as you try to understand all of this cycle stuff, and how to interpret the symptoms etc.
I think the people I know with IUDs have had variable experiences. Sorry I can't help you there...
Started Whole30 December 31, 2011
Integrated Leptin Reset/Jack Kruse plan Jan 13, 2012
Starting Weight: 174.8