Letrozole question!!

Samantha • Mommy of 2! TTC #3. Ectopic 3/29/18 Waiting on my 🌈👶🏼❤️

I took provera to bring on a AF and last night I started spotting. This morning there is more actual bleeding but what do I count as cd1? Yesterday or today? I’m supposed to start letrozole cd 3-7!!!