Ttc and testing

Kattie

I have the app ovia and of course it's going to waver with the dates and not be exactly correct. But it says my period isn't due until the 9th of June. But says I can test in 8 days? I'm 4 days past ovulation. I think I ovulated late. Because I took the opk and it was positive four days ago and I charted it. So when should I REALLY test. I'm confused.