OPK question!

Shelby
Hi ladies. These tests confuse me so much sometimes. I'll give some background before I ask my main question. 
AF ended a week ago on Thursday. The app says I will ovulate around the 6th, but I had EWCM On Monday and Tuesday, so Wednesday I picked up some OPKs and took one Wednesday night, yesterday morning, last night and this morning. I will post the photo to help with my main question which is:
None of these are positive for a surge, but does the darkness of the lines mean anything? Does a darker line mean you are getting closer to a surge, or do they mean nothing unless positive? I'm not sure if I did ovulate early or not!