Question about clomid and when to start

Colleen
Okay so AF has arrived friday and i am suppose to take first dose of clomid on cd3. I am not sure if friday or Saturday should count as cd1. Friday It was not spotting but was light flow. OBGYN said cd1 for me should be on day that my AF is heavier then spotting. So do I count friday as cd1? Or do I count today Saturday as cd1?