Ovulation test question

Kelsey • Mommy to a beautiful 5 year old little girl and handsome 3 year old little boy. Another sweet Baby boy coming in May!
I took my first ovulation test on Monday. There were two lines one was slightly lighter than the other repeated the test yesterday and today and got a clear negative. What I'm thinking happened is I had already ovulated before I tested. We bd'd the three nights leading up to my first ovulation test. I'm not worried that we missed it I'm just trying to figure out exactly how many DPO I am. Should Sunday be considered the day I ovulated?