Ovulated early?

Bizy • Rainbow Baby due October 2020🌈

I typically know when I ovulate, based on CM and I take an OPK to confirm. I usually O on CD12 (I have a 28C).. I started taking OPKs two days ago because we wanted to start tracking this month more closely. My first test wasn’t positive, but the second line was there. I tested yesterday and the line was fainter, and I just tested again and the line is even fainter than yesterday.

Does this happen leading UP to ovulation? Or did I perhaps ovulate early and the surge is going down?

I had CM yesterday, but that’s been it so far