I used the same test kit as you and I also thought I saw a faint line on mine but can’t be sure. Can spend a little more to get another kit which cost more but will give you specific results. No guessing required.
I guess blue dye test really very difficult to see.. always will show a faint shadow or line there. I retested today because I still have 1 extra kit but its almost similar.. since I'm seeing my gynae this noon, I shall ask for a blood test instead.