Is today or tomorrow CD1?

[mpayne186]

I started very light spotting 3 days ago. Tonight AF came as it normally does. Its fairly light and I'm expecting heavier flow by morning. In terms of charting and setting my ClearBlue Fertility Monitor, is today CD1, or will tomorrow be CD1? I thought I read some where that CD1 is the first sign of "regular" flow (whatever that is! lol) Advice? Thank you!

 

[xnmd1]

the first day of regular flow is CD1 so id say today

 

[burrr]

I disagree, if it came on in the evening, the next day is classed as day 1. This is what my fertility clinic told me when I was having treatments with them.