Here's two websites which i thought was good, to record down one's AF (Aunty Flora - another word for Menses)

www.cyclespage.com
- good to use to know when AF coming, if its late, as well as the average cycle. :)

www.fertilityfriend.com
- this recommend by friend who is ttc (Trying-to-conceive)
Notes down the usual day when AF reports, as well as temperature if ttc.
however, best to be BBT (Basal Body Thermometer?)

Also to note down when BD (baby dance - another word for sex la)
so as to accurately plan for a baby.

personally, have been using cyclespage for years!
As i tend to forget my next AF period, this act as a good gauge, to ensure i wont stain myself. wahahhaa