OPKs and Temping help

Lauren

Is it normal for OPKs to get darker, not hit positive, then light again? The 20th and 21st looked like the dye ran but I assumed they were negative. This is my first time Temping and using OPKs after a CP on the 7th.

Just trying to understand things. Thinking I might get a positive tomorrow since I had a temp drop this morning.