With IVF cycling they always say CD1 is the first day of full flow. I would therefore say today is your day 1. It is annoying how our bodies can be so changable! I have found that I always have full flow day one except when trying to count for IVF when I get light flow day one, two or even three and then full flow. SOOOO annoying isnt it!!
Good luck cycling!
Sazz