Evap?

I'm 3-5 days late for AF, I tested yesterday and got an extremely faint line. I'm not sure if it's an Evap or not. My nipples are very tender but only when I touch them. Other than that, I don't have many other symptoms. Could I still be pregnant? Have any of you not had an obvious positive test for a while after AF was due? Any advice/experiences are appreciated!! Thank you!!