I've been told to have some tests done on a particular day of my cycle to measure hormone levels. I'm a bit confused though - my period usually starts with 24 - 48 hours of dark red/brown discharge before the 'proper' bleeding starts. That then lasts for 3 days, then there's another 2 days of discharge at the other end. Do I count my period (cycle day 1) as beginning from the first sign of red discharge, or from when I start bleeding heavily?