I started taking opks on cycle day 9 which was the 4th. It was positive to my surprise. I really thought I'd have a few negative days before getting a positive. But I started having sore boobs and cramps a bit earlier so I went ahead and started testing. On cycle day 10 and 11 it was high but not at peak like it was on the 4th. And the days from then til now it's been negative. My last period was July 27-30. I'm pretty sure that I did ovulate maybe on the 5th the day after my positive because of cm, cramps, and my normal ovulation symptoms. But now according to my <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period apps</a> it's saying my expected period is in 8/9 days. I have normal 28 day periods. Is the apps just going off of ovulation ? Or does a period come early if you ovulate early? I'm confused as when I should expect it. On the 19th or the 23 which would be day 28.

Also I think had I taken an opk on the 3rd it would've have been positive by that afternoon because of how previous months have gone.

I've not had any more ovulation symptoms since about the 6th which also makes me think opks were right and I did ovulate early.