It's pretty rare for me to have a cycle anymore, due to opiates...So, don't forget that your meds also mess with your hormone levels. My trying to take hormone replacement to try and correct the issue resulted in having one that went on for several weeks...

I was always hypersensitive to birth control pills as well (pre RSD). The very lowest dosage always shut down my cycle and it would take 6-12 months for it to return after going off it.

Dr. Hooshmand link about RSD and estrogen.
http://www.rsdrx.com/rsdpuz4.0/puz_103.htm


Good explanation of the effect estrogen has on blood sugar, and while this refers to women that have had hysterectomies it relates to RSDers because we have reduced estrogen from the syndrome and the meds many of us take. Nasty vicious cycle...
http://www.hystersisters.com/vb2/article_97223.htm