TTC cycle start date question. Help!!!!

For ovulation tracking purposes, can I have your opinion on when I should count my start date. Yesterday I had very light spotting all day, around 8pm, it was a little heavier but not what I should be for my start. I went to bed and around 3 am this morning I got up to go to the bathroom and it was definately noticeable that I started. But for ovulation tracking purposes should I say I started yesterday or today? I'm only so worried bc I am out of town the weekend I'm supposed to be fertile 😩 I need help figuring out when I actually started so I can time the bd!!! Opinions? Advice? Help