Short surge??? Help

Brianna • Mommy to a girl born 9/12/2008.😇 10/26/18. MMC 5/20/19 🤰🏼 🌈 due in April 2020!

Has anyone experienced short surges? I had a positive digital on both my clear blue digital ovulation tests and well as two different opks around 4pm. I took another clear blue and opk around 7:30 and both were negative. Some confusing. Took another around 9:30 and they are a little darker again. Jw if this is an issue??