Defective test?

Took this last night (top) out of the blue because I was feeling VERY sick. (Thought it was the flu.) Got a bfn, threw it away, and didn't think anything of it. Noticed it in the trash this morning and saw a slight +, so I took another one (bottom).

The box says to disregard any results after 10 minutes. Could this just be a defective test?