Ovulation confusion

So earlier this month I was really confused. I had 4 positive yes from the Walgreens digital ovulation test. Then on the 4th day I bought the clear blue one & it said low fertility but when I got home & took out the test strip I saw this & it had 2 blue lines. Now this was the first time I ever used the clearblue digital too. What do you guys think ? Was the Walgreens right and I ovulated for 4 days or had a LH surge I should say? Was the clearblue right ? Low LH surge? What were the 2 blue lines on the test strip for the clearblue mean?