A pos opk can last how long?

Just when i thought I might have already O'ed, I've been getting a positive opk where the lines aren't getting any fainter.

(10/7)

11am : 1st peak reading on clearblue advanced digi

5pm : positive on clearblue easy

930pm : negative on first response

2am : positive on clearblue easy

(11/7)

1pm : positive on both first response & clearblue easy

430pm : positive on first response

1215am : positive on clearblue easy

(12/7)

130pm : positive on first response

Am i not ovulating? (Sry tmi, dh and i dtd one day before the peak and throughout.) What is happening?