TMI - period & ovulation test

I had spotting on Thursday & Friday, a medium flow today and now it's the brown thick stuff, so does that mean it's the end of my period and do I start testing with the 1st response digital ovulation tests tomorrow if I have nothing on my tampon tomorrow do I start testing then or wait till Monday which is day 5 of my cycle like the box says? I really don't want to miss my high day this month.