Is it possible to still test negative??

I ovulated on the 31st of last month (July). Husband and I tried every day during my “fertile window.” Today I am 12 dpo. I have been testing every day and all have been negative. At 11 dpo I thought I saw a very faint line, but I think it was just line eyes or and indent(will attach pic). Is it possible to be pregnant and still test negative at 12 dpo? I’ve been using First Response Gold.