Opk pros help me please. Okay I got my first very dark positive on the 23rd...then got the same…

Opk pros help me please. Okay I got my first very dark positive on the 23rd...then got the same exact result on the 24th 25th and the 26th. Then it began to lighten on the 27th finally and then was completely lightened by the 28th. I hear they say to go by the first darkest positive? but would you think that the egg didnt release until it starts lightening up? Please excuse me as I am very confused, and overly excited bc I tried preseed for the first time all month lol and I would love to keep up with my dpo. lol here is a pic in order from top to bottom from the 23rd- 28th