Crazy Janey - your estrogen theory may be something! I rarely have a period, maybe once every 5-6 months, lasts only 1 day and very, very light.
The first night I couldn't sleep happened to be the day I started my period! I even commented to my friend that I was bleeding like I did as a teenager - sorry TMI.
I go for my 1 week post-op tomorrow so I will inquire for all us non-sleeping estrogen ridden sleevers!!
Thanks for all your comments